There are numerous things I have learned by trial and much error over the years. As they pop into my head I will try to compile some of them and post them here. Tell me your little tidbits or pearls of wisdom.
- bike fitting: when considering saddle tilt, remember that a saddle is meant to flex and give some to relieve pressure as your legs pedal in a reciprocal fashion. just because a saddle is set level when it's built does not mean it remains level when you sit on it (and it then flexes). you need to consider the weighted tilt of the saddle.
- training: stay away from moderate duration and moderate intensity. If you're going to go long, GO REALLY LONG (and easy on the intensity). If you're going to ride very hard, then RIDE VERY HARD (and short on the duration). Beware of the 2 hour group ride.
- fitting: since the rider is 80% of the drag on the bike, don't sweat too much not having the "most" aerodynamic frame. what is "most" aero anyway is up for debate at times -- was the aero bike in question tested by itself or with a rider on it?; were the yaw angles where it tested well, typical angles you would see in real life anyway?; can you ride in the aggressive position that the bike is built to optimize?
- weight: when agonizing over a new light piece of equipment, remember to consider the weight savings as a function of the bike AND rider's total weight. For example buying a brakeset that is 100g lighter sounds great, but if you weigh 81 kg and your bike weighs 7.5 kg then that's not a 3.3% reduction in weight, but rather only a 0.3% reduction. Would you spend $200 on insulation for your house if it only saved you 45 cents a month on your bill?
- training: stretching is always a contentious issue. Some people
- equipment: clincher tires actually test with lower rolling resistance than tubulars, but only when expensive latex tubes are used. If you're using butyl tubes, the tubulars will roll better.
- want to make the most improvement of efficiency on your bike? 1. get a proper fit, 2. work on your pedal stroke, 3. upgrade your wheels to something more aerodynamic and/or with a lower rim weight
Thursday, December 3, 2009
Monday, November 23, 2009
the ultimate tool
I have never been a car guy. I never got into tools or working on cars (primarily because cars were and are nearly impossible to do any work on anymore, but oh well). Now, however, I really enjoy working on bikes. When you see a lot of clients, like I do, especially in the intense one-on-one nature of a bike fit, you are "on" a lot. It's like being an educator -- some days I talk all day long; or at least it feels that way. I love when I can steal away and quietly work on client's bikes -- it is pretty therapeutic.
So now I love really nice tools, and MC turned me onto Efficient Velo Tools, which is like a Toys'R'Us for geek bike mechanics like myself. I ordered the Smoothie Headset Press because it is the only one I've found that can press the sometimes long head tubes I build in the custom market.
The tool works like a dream, thanks in part to being able to get leverage at the bottom and top of the press (see the vise grip clamp at the bottom in the pics below), and a nice bearing underneath the "wingnut", which keeps the pressing action extra smooth.
The headset is my old standard -- a Chris King one and an eigth, in red with the stealthy Sotto Voce decals.
The bike is a Seven Sola S (full Ti)single speed 29er with slider dropouts (i'll post more on this bike when it's done).
the headset
the frame
The tool
cups on press
ready for action
finished
So now I love really nice tools, and MC turned me onto Efficient Velo Tools, which is like a Toys'R'Us for geek bike mechanics like myself. I ordered the Smoothie Headset Press because it is the only one I've found that can press the sometimes long head tubes I build in the custom market.
The tool works like a dream, thanks in part to being able to get leverage at the bottom and top of the press (see the vise grip clamp at the bottom in the pics below), and a nice bearing underneath the "wingnut", which keeps the pressing action extra smooth.
The headset is my old standard -- a Chris King one and an eigth, in red with the stealthy Sotto Voce decals.
The bike is a Seven Sola S (full Ti)single speed 29er with slider dropouts (i'll post more on this bike when it's done).
the headset
the frame
The tool
cups on press
ready for action
finished
Friday, October 30, 2009
"Mid-Foot" running form and Newton Running Shoes
Here at The Bicycle Studio we are known for our bikes and bike fitting. As a physical therapist, I treat all manner of athletes and in addition to cycling I run quite a bit (most weeks more than I bike), and I have been doing Ironman triathlons for about 10 years, and marathons for about 15 years. Today I am going to discuss running. I have been studying running mechanics and research related to running form for about 15 years now. There is a lot of information out there, not all of it good, but here I will specifically go into running shoes.
I began running for fun and competition almost 25 years ago so as far as running shoes go, I began smack dab in the middle of the running shoe revolution. Shoe companies competing for the most cushioning, or motion-controlling, or energy-returning device available. A lot of gimmicks out there and hindsight being what it is, we are beginning to see that it was solving a problem that didn't exist. In fact, the research is bearing out that these shoes may be the reason for a number of common running injuries, like plantar fasciitis, achilles tendinitis, and generalized knee pain.
The issue with cushioning running shoes is that they alter running mechanics in a profound way. Simply, they make it easier to land on your heels, and in fact with most of these shoes they make it nearly impossible to land anywhere else. I won't get too far into this as there is a lot written about this topic already -- read Born to Run, Chi Running, Programmed to Run, and Lore of Running.
The basic idea behind the mid-foot running revolution is that landing on your heel makes you land with your foot in front of you. In order to progress to the next stride your quads have to eccentrically absorb that impact as your center of gravity then passess over your planted foot and then the quads, hip extensors, and calf muscles must push off in order to propel you forward. When that heel hits the ground in front of you, you have to decelerate first and then accelerate again. It's almost as if that heel out on front of you is STOP sign, repetitively slowing you down and requiring you to expend energy to speed back up every stride. There are a lot of impact forces associated with this running style.
When you land on your mid-foot, you have to land with your foot near or exactly underneath you, so your body/center of mass naturally carries over the planted foot on the momentum you have already generated. Your legs muscles do not have to eccentrically absorb each impact because the foot is planted already far enough behind you that this momentum is enough and less knee flexion/extension occurs. Running in this way, while foreign at first, will feel like you are taking smaller steps (which you are) and has a lighter more nimble feel to it. There is a break-in period where you have to keep re-training your body to stick with this new form. Some calf muscle soreness is normal, but with consistent work it becomes more natural. I can say from personal experience you will have less overall leg soreness and fewer injuries because you have significantly reduced the jarring effect of your stride. I have been a proponent of this running form for almost ten years, and now with the book Chi Running becoming so popular, it has really become more mainstream (there was a book released years before Chi Running called Programmed to Run which touched very nicely on the issue)
The Newton running shoes embrace this "mid-foot strike" running stride in a ground-up design of their shoe to make landing on your heel less likely. It has a lower profile heel and pronounced knobs on the front of the shoe (underneath the metatarsals). When I first laced these up, I noticed they make it nearly impossible to land on your heels, which is the idea, I guess. I did a number of runs on them and I would say they accomplish this task admirably.
But I didn't like 'em.
I think because I have been working on and using this form for years may have made my transition to these shoes less revelatory. In my experience, I found when I changed to shoes with less heel cushioning (lower profile overall) my form cleaned up very nicely and I was able to pitter patter my way around the trails much lighter and easier (and with much more enjoyment). The lugs on the forefoot of the Newtons
felt intrusive, and while they likely made a mid-foot strike more likely for a newbie to this way of running, they seemed to get in the way, or at least seem superfluous. I actually developed some 4th metatarsal soreness after using them on a number of very moderate duration runs.
And then there's the cost. The ones I used were $175. I know that running shoes are quickly working there way up there in price, but these were still in the deep end of the price pool. When I made the transition to lower profile, less cushioning shoes
Idea behind the shoe, one of the added benefits of these was the low cost. I run in the throw-back Saucony Jazz Low Pro
which you can get for under $50, so the jump to a Newton was quite a leap.
All in all, I think that Newton has the right idea -- running with more mid-foot form is better, but I don't know that the shoe is entirely necessary. It does solve the problem of heel striking, but I don't think it is the only way (nor the cheapest way) to go about it.
Wednesday, September 16, 2009
Guru Sidero Steel Road bike -- closeout sale
Okay, here's your big chance. I am closing out this demo bike to make room for more stuff coming in. It should fit people in the 5'5" range in height.
It has never been ridden.
You can read more of the build and sizing here.
This is a beautiful steel similar to True Temper's S3 air-hardened blend, but Guru has put their own name to it.
Full SRAM Force build, this usually retails for just shy of $4000. I am listing it today for $2800 plus shipping. Payment by PayPal only, first one to fund it gets it.
Questions and PayPal taken at: john at thresholdsport dot com
It has never been ridden.
You can read more of the build and sizing here.
This is a beautiful steel similar to True Temper's S3 air-hardened blend, but Guru has put their own name to it.
Full SRAM Force build, this usually retails for just shy of $4000. I am listing it today for $2800 plus shipping. Payment by PayPal only, first one to fund it gets it.
Questions and PayPal taken at: john at thresholdsport dot com
Wednesday, September 9, 2009
Cleats forward? Cleats Back?
Is economy of competitive cyclists affected by the anterior–posterior foot position on the pedal? J.R. Van Sickle Jr, M.L. Hull; Journal of Biomechanics 40 (2007) 1262–1267
When doing a bike fitting, changing cleat set-up is the keystone to a good outcome. While we have three contact points on the bike (hands, butt, feet) and all three CAN affect mechanics up and down the chain (i.e. if your left hand goes numb and so you hold it differently on the bar this can affect your shoulder position and induce a twist on the spine, which can affect how your sit bones rest on the seat....) the cleats/foot interface is always the most difficult to address, but also has the greatest gain associated with a correct adjustment. When you nail he cleat position it can often be a dramatic shift from a herky-jerky pedal stroke to a smooth elliptical rhythm.
The only way to truly read the necessary movements about the cleat is with an dynamic 3D analysis as is provided by the infrared systems (like the Retul). Video lacks the on-the-fly capability, is not taking measurements in 3 dimensions, and lacks the accuracy necessary to really make sound decisions. Prior to the Retul system being available, using the older methods of video, goniometers, plumb lines etc, we were just not able to address these small but, as we continue to find out, incredibly important factors.
So the article referenced above deals with one of the more coarse adjustments of the cleat -- the fore and aft positioning. This makes perfect sense because there is not much research out there about bike fitting, and specifically little regarding proper cleat alignment. (Incidentally the main adjustments to the cleats are the fore-aft, medial-lateral, varus-valgus wedging, and shimming for leg length under the cleat.) Marty Hull is one of the authors of this article, and if you're in interested in cycling and don't know who he is, you should. He has probably done more research into the mechanics of cycling than any other person on the planet. If you'd like to learn more about the ins and outs of cycling mechanics, you could do worse than reading his stuff.
In this study trained cyclists were tested at 90% of VO2 max with three different cleat positions: (1) standard forefoot placement (roughly under the metatarsals or "balls" of the feet), (2) midway between the rear of the calcaneous and the metatarsal heads, and (3) midway between 1 and 2.
They were tested on three separate days (with a rest day before each test day) and tested on all three cleat positions each day (in random order). They then measured how efficient each position was by way of how much oxygen was "used" (VO2) in the testing period of each cleat position. In simplistic terms, think of VO2 as the amount of oxygen that is used up (units in mL/min).
They found that there was no difference in efficiency with any of the cleat positions, so the more rear-ward positioned cleats were not an improvement in their cycling economy (more on why the rear-ward cleats might be more efficient later). So this seems to show that mounting your cleats further back on the shoe is not more efficient, but I, along with the authors, believe that there could be good reason why you would still opt for a "mid-foot" or "arch" cleat placement.
The first reason is Achilles/calf problems. When the cleats are further back on the shoe, the foot is "shortened" and so there is less of a lever arm about the ankle and so less muscular stabilization is required to keep the ankle relatively still as the main cycling muscles (quadriceps, gluteals, hamstrings) exert their force on the pedal. We do move our ankle while we pedal ("ankling") roughly 15-25 degrees, but the calves only provide about 7.5% of the total power output, so for many athletes with Achilles problems moving the cleat back can reduce the strain here and keep injuries away.
The next reason you may move cleats back is if you have foot numbness, tingling or pain issues. This may be because you have had prior foot problems (morton's neuromaor bunion, etc)
or maybe you are an ultra-endurance cyclist (the longer we ride, obviously the more pressure is exerted on our feet, but the feet swell slightly, making the shoes relatively tighter and placing more pressure on the nerves and soft-tissue of the forefoot). Many of the Race Across America (RAAM) competitors have been using mid-foot cleat placemen for years because when you push down on your pedals over 100,000 times a day for more than a week those tissues in your forefoot can get sensitive. If you aren't pressing through your forefoot, however, (and you push through the more hearty, muscled mid-foot) it cannot get sore.
You may also shift those cleats back simply if you have a hard time finding a perfect fitting shoe. Many "European" cut shoes are a hard fit for some. Poor fit can mean more pressure, and I've found that a slight shift rear-wards of the cleat can buy you some comfort.
The authors of this study were testing the theory that by moving the cleats back and having a reduction in the force requirement of the calf muscles, an improvement in economy (or efficiency) may be had. While an improvement in efficiency was not seen in this study, I think there is still hope, and the reason is motor planning. In my 14 years as a physical therapist I see people make improvements from many changes that we make to their mechanics, but those improvements don't become fully realized or don't fully coalesce until the person has mastered that new motor plan.
This process can take a few weeks or longer depending on how complex the task is. I have always believed that the pedal stroke is a lot more complicated than most people give it credit. Sure anyone can pedal a bike, but there are few people that can exert a nearly uniform force on the pedals for a majority of the pedaling cycle. In my research of pedal stroke analysis, I found early on that no one (NO ONE) can push/pull through the entire pedal stroke. Everyone, even the best pedalers cannot get their foot out of the way fast enough on the back stroke and so the put a "negative torque" on the cranks.
Then consider being able to activate the quads and hip extensors at that precise (and earliest) moment, to initiate the power stroke in the most efficient way -- the whole cycle, done well, requires a lot of coordination. Need further proof? Take 10 experienced cyclists and get them on a trainer for some one-leg pedaling drills. You will see many floundering individuals. Not withstanding this guy:
So given the complexity of pedaling a bike, with an uninterrupted block of time to adapt to the new cleat position, I think you will find that the improvement in economy would be seen. I have no hard proof of this, of course, just a hunch.
In my own personal experience I find that having my cleats back has prevented foot and heel problems when I was doing 24-hour races, helped me run better off the bike in Ironman races, and generally gave me the feeling of having very solid, consistent power output on the road bike.
It's not for everyone, but many people can benefit from this simple adjustment
When doing a bike fitting, changing cleat set-up is the keystone to a good outcome. While we have three contact points on the bike (hands, butt, feet) and all three CAN affect mechanics up and down the chain (i.e. if your left hand goes numb and so you hold it differently on the bar this can affect your shoulder position and induce a twist on the spine, which can affect how your sit bones rest on the seat....) the cleats/foot interface is always the most difficult to address, but also has the greatest gain associated with a correct adjustment. When you nail he cleat position it can often be a dramatic shift from a herky-jerky pedal stroke to a smooth elliptical rhythm.
The only way to truly read the necessary movements about the cleat is with an dynamic 3D analysis as is provided by the infrared systems (like the Retul). Video lacks the on-the-fly capability, is not taking measurements in 3 dimensions, and lacks the accuracy necessary to really make sound decisions. Prior to the Retul system being available, using the older methods of video, goniometers, plumb lines etc, we were just not able to address these small but, as we continue to find out, incredibly important factors.
So the article referenced above deals with one of the more coarse adjustments of the cleat -- the fore and aft positioning. This makes perfect sense because there is not much research out there about bike fitting, and specifically little regarding proper cleat alignment. (Incidentally the main adjustments to the cleats are the fore-aft, medial-lateral, varus-valgus wedging, and shimming for leg length under the cleat.) Marty Hull is one of the authors of this article, and if you're in interested in cycling and don't know who he is, you should. He has probably done more research into the mechanics of cycling than any other person on the planet. If you'd like to learn more about the ins and outs of cycling mechanics, you could do worse than reading his stuff.
In this study trained cyclists were tested at 90% of VO2 max with three different cleat positions: (1) standard forefoot placement (roughly under the metatarsals or "balls" of the feet), (2) midway between the rear of the calcaneous and the metatarsal heads, and (3) midway between 1 and 2.
They were tested on three separate days (with a rest day before each test day) and tested on all three cleat positions each day (in random order). They then measured how efficient each position was by way of how much oxygen was "used" (VO2) in the testing period of each cleat position. In simplistic terms, think of VO2 as the amount of oxygen that is used up (units in mL/min).
They found that there was no difference in efficiency with any of the cleat positions, so the more rear-ward positioned cleats were not an improvement in their cycling economy (more on why the rear-ward cleats might be more efficient later). So this seems to show that mounting your cleats further back on the shoe is not more efficient, but I, along with the authors, believe that there could be good reason why you would still opt for a "mid-foot" or "arch" cleat placement.
The first reason is Achilles/calf problems. When the cleats are further back on the shoe, the foot is "shortened" and so there is less of a lever arm about the ankle and so less muscular stabilization is required to keep the ankle relatively still as the main cycling muscles (quadriceps, gluteals, hamstrings) exert their force on the pedal. We do move our ankle while we pedal ("ankling") roughly 15-25 degrees, but the calves only provide about 7.5% of the total power output, so for many athletes with Achilles problems moving the cleat back can reduce the strain here and keep injuries away.
The next reason you may move cleats back is if you have foot numbness, tingling or pain issues. This may be because you have had prior foot problems (morton's neuromaor bunion, etc)
or maybe you are an ultra-endurance cyclist (the longer we ride, obviously the more pressure is exerted on our feet, but the feet swell slightly, making the shoes relatively tighter and placing more pressure on the nerves and soft-tissue of the forefoot). Many of the Race Across America (RAAM) competitors have been using mid-foot cleat placemen for years because when you push down on your pedals over 100,000 times a day for more than a week those tissues in your forefoot can get sensitive. If you aren't pressing through your forefoot, however, (and you push through the more hearty, muscled mid-foot) it cannot get sore.You may also shift those cleats back simply if you have a hard time finding a perfect fitting shoe. Many "European" cut shoes are a hard fit for some. Poor fit can mean more pressure, and I've found that a slight shift rear-wards of the cleat can buy you some comfort.
The authors of this study were testing the theory that by moving the cleats back and having a reduction in the force requirement of the calf muscles, an improvement in economy (or efficiency) may be had. While an improvement in efficiency was not seen in this study, I think there is still hope, and the reason is motor planning. In my 14 years as a physical therapist I see people make improvements from many changes that we make to their mechanics, but those improvements don't become fully realized or don't fully coalesce until the person has mastered that new motor plan.
This process can take a few weeks or longer depending on how complex the task is. I have always believed that the pedal stroke is a lot more complicated than most people give it credit. Sure anyone can pedal a bike, but there are few people that can exert a nearly uniform force on the pedals for a majority of the pedaling cycle. In my research of pedal stroke analysis, I found early on that no one (NO ONE) can push/pull through the entire pedal stroke. Everyone, even the best pedalers cannot get their foot out of the way fast enough on the back stroke and so the put a "negative torque" on the cranks.
Then consider being able to activate the quads and hip extensors at that precise (and earliest) moment, to initiate the power stroke in the most efficient way -- the whole cycle, done well, requires a lot of coordination. Need further proof? Take 10 experienced cyclists and get them on a trainer for some one-leg pedaling drills. You will see many floundering individuals. Not withstanding this guy:
So given the complexity of pedaling a bike, with an uninterrupted block of time to adapt to the new cleat position, I think you will find that the improvement in economy would be seen. I have no hard proof of this, of course, just a hunch.
In my own personal experience I find that having my cleats back has prevented foot and heel problems when I was doing 24-hour races, helped me run better off the bike in Ironman races, and generally gave me the feeling of having very solid, consistent power output on the road bike.
It's not for everyone, but many people can benefit from this simple adjustment
Monday, September 7, 2009
Get a fit first.....please!
I am begging anyone who reads this blog to do your friends, family, co-workers, arch-enemies, accountant a favor and tell everyone you know to get a proper bike sizing (by a professional) before they buy a bike.
It happened again -- I saw a client late last week that had just spent $3500 on a bike and it is the wrong size. They said that the salesperson claimed they would do a bike fit to make certain that the client got what they needed, but after some digging it appears the "bike fit" consisted of little more than watching the client ride around the parking lot and declaring, "Looks good!"
It can be difficult to know who to trust. My advice: Don't trust the guy (or gal) who is trying to sell you the bike in front of you. Especially if they don't spend at least 20 to 30 minutes figuring out what size you need. They should be asking you all sorts of questions about you and your riding:
How often do you ride?
How many miles per ride? per week?
Do you plan to road race? Triathlon?
What don't you like about your current bike?
Any injuries, related to the bike or otherwise?
And about 2 dozen more to boot.
At this point it'd be okay to get you on a bike or, even better, on your current bike (preferably on the trainer) and watch you ride. This is where I differ from most bike shops -- I don't think a "quick fit" suffices, in which they have you on the bike for about 5 minutes total. This is the time where the fitter should be asking a lot more questions while you are on the bike as they watch you pedal from multiple angles. I usually hook up the Retul and take a shot of each side to get more information. If you are on a bike less than 15 minutes, or if the fitter isn't asking appropriate bike specific questions you should be wary of the fit advice you are given by this individual.
Even if you are buying a bike for $1200 or less, it is worth getting a bike fit/sizing. I charge $250 for my bike fit service, but that includes a pre-purchase bike sizing session (which usually lasts about 45 minutes and even shows you how to measure the bikes you may look at to make sure they are the best fit for you, if you don't plan on buying a bike from me), a complete dynamic bike fitting (about 1.5 - 2 hours) and a follow up (again about 45 minutes) a few weeks down the line to put the final tweaks on the set-up.
But the bike is only $1000? And the fitting is a quarter of that cost -- that can't be worth it, right? Well, I've seen a lot of bikes in the wrong size, and whether it's $1000 or $7000, if it doesn't fit, then it can become a rather expensive coat rack out in the garage.
It happened again -- I saw a client late last week that had just spent $3500 on a bike and it is the wrong size. They said that the salesperson claimed they would do a bike fit to make certain that the client got what they needed, but after some digging it appears the "bike fit" consisted of little more than watching the client ride around the parking lot and declaring, "Looks good!"
It can be difficult to know who to trust. My advice: Don't trust the guy (or gal) who is trying to sell you the bike in front of you. Especially if they don't spend at least 20 to 30 minutes figuring out what size you need. They should be asking you all sorts of questions about you and your riding:
How often do you ride?
How many miles per ride? per week?
Do you plan to road race? Triathlon?
What don't you like about your current bike?
Any injuries, related to the bike or otherwise?
And about 2 dozen more to boot.
At this point it'd be okay to get you on a bike or, even better, on your current bike (preferably on the trainer) and watch you ride. This is where I differ from most bike shops -- I don't think a "quick fit" suffices, in which they have you on the bike for about 5 minutes total. This is the time where the fitter should be asking a lot more questions while you are on the bike as they watch you pedal from multiple angles. I usually hook up the Retul and take a shot of each side to get more information. If you are on a bike less than 15 minutes, or if the fitter isn't asking appropriate bike specific questions you should be wary of the fit advice you are given by this individual.
Even if you are buying a bike for $1200 or less, it is worth getting a bike fit/sizing. I charge $250 for my bike fit service, but that includes a pre-purchase bike sizing session (which usually lasts about 45 minutes and even shows you how to measure the bikes you may look at to make sure they are the best fit for you, if you don't plan on buying a bike from me), a complete dynamic bike fitting (about 1.5 - 2 hours) and a follow up (again about 45 minutes) a few weeks down the line to put the final tweaks on the set-up.
But the bike is only $1000? And the fitting is a quarter of that cost -- that can't be worth it, right? Well, I've seen a lot of bikes in the wrong size, and whether it's $1000 or $7000, if it doesn't fit, then it can become a rather expensive coat rack out in the garage.
Wednesday, September 2, 2009
Sorry..
...I've been away for awhile. Life happened, but I am working back into the swing of things. I've been playing catch up and have done about 25 bike fits in the last 3 weeks, so I think I will have some good ammo to put out there. I may even have a hand-made steel road bike to sell at a discount as well. Stay tuned...
Tuesday, July 7, 2009
The Womens Specific Myth
I get asked a lot from my female clients that come to me for a fitting before they buy a bike (which is the right way to do it -- get a professional sizing done first, THEN buy a new bike and complete the fitting process on it) wondering which "womens specific" bike they should get.
First let me say that, certainly there are many ladies out there that are quite comfortable on their womens specific bike; and they can work out great. But in general, the idea that women need different geometry is a myth.
Let's start by looking at it from an industry standpoint. What are the major bike manufacturers doing? They seem to go one of two ways:
1. They take the men's line of bikes, eliminating the sizes over 57cm, stick narrow handlebars, 170mm cranks, a softer seat, and accent the paint with pink or purple.
A good example of this is Cannondale:
Compare the "like-sized" bikes and you'll find no difference whatsoever in their geometry; same effective top tube, head tube, angles, standover, etc. They use narrower handlebars, presumably a shorter stem or straighter (non-setback) seatpost because they tout a shorter cockpit length, and shorter cranks. (Also girlie colors.)
2. Others do all of the above and then shorten the top tube (and possibly lengthen the head tube).
The truth is that some women do well with option number 1 and others do well with option number 2 .......
........but so do most men.
Taking the 2nd option, where they actually change the length of a few tubes on the bike, assumes that relative to their height women have shorter torsos and/or shorter arms (and possibly less flexibility). While many women do have shorter torsos (and therefore are long legged) their numbers do not outnumber their more proportionate or long-torsoed breathren in great enough numbers to warrant a change in all their bike geometry, I think. Even if you accept that long-legged, short-torsoed women represent the center of the bell curve and have that large of a representation, then changes that the bike companies make to design a "woman's" bike are often not different enough to accommodate the women who actually need it -- on the order of a 1 - 2 centimeter shorter top tube and possibly 1 - 1.5 cm longer on the head tube.
Incidentally, this is the approach that Specialized, Look, Cervelo, among many others take when designing a "higher handlebar position bike" or one they tout to be used in Paris-Roubaix. These are designed for men and women. So it's good that they make these changes, but often I don't think they are completely filling the market niches -- which is why when I build so many custom bikes for people who don't fit these niches.
So I know, now it sounds like that first I was complaining that they make the changes at all and then I complain that they need to make even greater changes. But that's what I think they should do....
.....but they should do the same thing for the men's bikes as well. They should have two or three *grades* of sizing from more aggressive to more relaxed.
Some companies are doing this to a small degree, but, again, usually the changes don't go far enough. Or the more relaxed geometries available are built like Bradley Fighting Vehicles and don't come in a performance package at all. I don't think it's wrong for people to want to ride their bikes hard and have nice components and wheels WHILE being comfortable. Our cycling population is getting older, but a lot of these riders still want to compete or at least continue doing big rides.
So I'm okay with companies NOT changing the geometry specifically for their women's bikes. I'm also okay with them changing the geometry -- it just doesn't need to be "womens specific." Even riders with Y chromosomes need geometry adjustment to optimize their fit.
As long as the stock bike manufacturers continue to err on the side of producing bike geometry with a racing-inspired pedigree, this will continue to be an issue. Unfortunately many cyclists will be sold a bike that does not match their riding strengths, simply because it is all that is available.
Custom bike manufacturers (like Seven Cycles) should continue to benefit from this oversight, especially as the cost of a stock bike and a custom bike continue to get closer and closer together. (Take a look at Seven's Gateway Program and then look at some of the cost of Specialized's Tarmac line, Trek's Madone, Cannondale's SuperSix -- many of those stock bikes get up close to $10,000 in their higher iterations!)
So when anyone (man or woman) is looking for a new bike, find out first what size bike you need and if any special considerations to the geometry of the bike ought to be made. There may be a stock option out there for you. If you think your current bike and fit are pretty good take a look at the setup -- if you have a threaded stem that is set to the "Minimum Insert" line or your stem is short length and/or high rise, then you might be in need of some additional adaptations to your bike geometry.
Why not just have the high rise or short stem on there (or the saddle slid all the way forward or backward on the rails for that matter)?
The problem with making these changes is that the handling of the bike is not built around these set-ups. These changes can work to make the bike fit better and be more comfortable, but they can also begin to affect the handling and the balance of the bike.
It's bad enough that the big stock manufacturers make forks with only 1 or 2 offsets and rakes to use on all their bikes -- from their 62cm down to their 49cm bikes.
(SIDE NOTE: Very small bikes and very big bikes should have forks with different offsets, but this costs money, so there are very limited options in forks out there and the big bike companies try to make up the difference with the head angles of the bikes. When doing this, one end of the spectrum -- either the big or the small -- will have compromised handling. Some of the companies, when listing the geometry for different sizes will even list some of the fork offsets and not list the others, saying they are "proprietary". Having used the Zin to log in the geometry and setup of my client's bikes -- which gives you fork rake and trail among many other measurements -- I can tell you that many times the rake of the fork is not different from the other listed sizes, the manufacturer just chooses to hide the fact that it is the same fork.)
So then when we change the handlebar height or seat fore-aft significantly on these bikes the handling and safety can sometimes suffer.
So do some research, go see a professional bike fitter that can help you find what will work best for you, and if you plan to spend more than $3000, don't discount a custom bike if it suits your needs better than the stock offerings.
Ride well.
First let me say that, certainly there are many ladies out there that are quite comfortable on their womens specific bike; and they can work out great. But in general, the idea that women need different geometry is a myth.
Let's start by looking at it from an industry standpoint. What are the major bike manufacturers doing? They seem to go one of two ways:
1. They take the men's line of bikes, eliminating the sizes over 57cm, stick narrow handlebars, 170mm cranks, a softer seat, and accent the paint with pink or purple.
A good example of this is Cannondale:
Compare the "like-sized" bikes and you'll find no difference whatsoever in their geometry; same effective top tube, head tube, angles, standover, etc. They use narrower handlebars, presumably a shorter stem or straighter (non-setback) seatpost because they tout a shorter cockpit length, and shorter cranks. (Also girlie colors.)
2. Others do all of the above and then shorten the top tube (and possibly lengthen the head tube).
The truth is that some women do well with option number 1 and others do well with option number 2 .......
........but so do most men.
Taking the 2nd option, where they actually change the length of a few tubes on the bike, assumes that relative to their height women have shorter torsos and/or shorter arms (and possibly less flexibility). While many women do have shorter torsos (and therefore are long legged) their numbers do not outnumber their more proportionate or long-torsoed breathren in great enough numbers to warrant a change in all their bike geometry, I think. Even if you accept that long-legged, short-torsoed women represent the center of the bell curve and have that large of a representation, then changes that the bike companies make to design a "woman's" bike are often not different enough to accommodate the women who actually need it -- on the order of a 1 - 2 centimeter shorter top tube and possibly 1 - 1.5 cm longer on the head tube.
Incidentally, this is the approach that Specialized, Look, Cervelo, among many others take when designing a "higher handlebar position bike" or one they tout to be used in Paris-Roubaix. These are designed for men and women. So it's good that they make these changes, but often I don't think they are completely filling the market niches -- which is why when I build so many custom bikes for people who don't fit these niches.
So I know, now it sounds like that first I was complaining that they make the changes at all and then I complain that they need to make even greater changes. But that's what I think they should do....
.....but they should do the same thing for the men's bikes as well. They should have two or three *grades* of sizing from more aggressive to more relaxed.
Some companies are doing this to a small degree, but, again, usually the changes don't go far enough. Or the more relaxed geometries available are built like Bradley Fighting Vehicles and don't come in a performance package at all. I don't think it's wrong for people to want to ride their bikes hard and have nice components and wheels WHILE being comfortable. Our cycling population is getting older, but a lot of these riders still want to compete or at least continue doing big rides.
So I'm okay with companies NOT changing the geometry specifically for their women's bikes. I'm also okay with them changing the geometry -- it just doesn't need to be "womens specific." Even riders with Y chromosomes need geometry adjustment to optimize their fit.
As long as the stock bike manufacturers continue to err on the side of producing bike geometry with a racing-inspired pedigree, this will continue to be an issue. Unfortunately many cyclists will be sold a bike that does not match their riding strengths, simply because it is all that is available.
Custom bike manufacturers (like Seven Cycles) should continue to benefit from this oversight, especially as the cost of a stock bike and a custom bike continue to get closer and closer together. (Take a look at Seven's Gateway Program and then look at some of the cost of Specialized's Tarmac line, Trek's Madone, Cannondale's SuperSix -- many of those stock bikes get up close to $10,000 in their higher iterations!)
So when anyone (man or woman) is looking for a new bike, find out first what size bike you need and if any special considerations to the geometry of the bike ought to be made. There may be a stock option out there for you. If you think your current bike and fit are pretty good take a look at the setup -- if you have a threaded stem that is set to the "Minimum Insert" line or your stem is short length and/or high rise, then you might be in need of some additional adaptations to your bike geometry.
Why not just have the high rise or short stem on there (or the saddle slid all the way forward or backward on the rails for that matter)?
The problem with making these changes is that the handling of the bike is not built around these set-ups. These changes can work to make the bike fit better and be more comfortable, but they can also begin to affect the handling and the balance of the bike.
It's bad enough that the big stock manufacturers make forks with only 1 or 2 offsets and rakes to use on all their bikes -- from their 62cm down to their 49cm bikes.
(SIDE NOTE: Very small bikes and very big bikes should have forks with different offsets, but this costs money, so there are very limited options in forks out there and the big bike companies try to make up the difference with the head angles of the bikes. When doing this, one end of the spectrum -- either the big or the small -- will have compromised handling. Some of the companies, when listing the geometry for different sizes will even list some of the fork offsets and not list the others, saying they are "proprietary". Having used the Zin to log in the geometry and setup of my client's bikes -- which gives you fork rake and trail among many other measurements -- I can tell you that many times the rake of the fork is not different from the other listed sizes, the manufacturer just chooses to hide the fact that it is the same fork.)
So then when we change the handlebar height or seat fore-aft significantly on these bikes the handling and safety can sometimes suffer.
So do some research, go see a professional bike fitter that can help you find what will work best for you, and if you plan to spend more than $3000, don't discount a custom bike if it suits your needs better than the stock offerings.
Ride well.
Wednesday, June 24, 2009
Felt B2 triathlon bike fit
I'm just recovering from a weekend of doing bike fits out of town. Occasionally I do this -- mostly around western Colorado and eastern Utah. When I have 3 or more interested clients (that seems to be my comfortable threshold right now for a proper "driving time/fitting fee" ratio -- at least for a 2 - 2.5 hour drive) I will make the trip out to them and set up in a corner somewhere all my equipment.
The Retul travels quite well. It packs away neatly into (what I am told is) a gun case. The most difficult thing to plan for is to have enough parts and equipment for as many possible fitting changes as possible. Carrying a few dozen stems of various sizes is no problem -- it's the handlebars (because of their size), and seatposts (too many different diameters) that are tough.
So anyway, I was in beautiful Basalt, Colorado this Saturday and Sunday to see a number of clients. I ended up doing about 11 hours worth of fittings on Saturday and another 3 hours on Sunday, so you can begin to get an idea of why I am "recovering".
Lots of very nice people, ages ranging from in their 30's to the upper 70's. Yep, you read that right. There are some very fit folks out in this part of the country.
One client that was a lot of fun was Dave C. He is an avid long distance triathlete; he just finished a 70.3 in Boise the week before. He is very fit, motivated, and attentive -- your basic Type A triathlete. He listened very well and asked a lot of good questions - exactly the type of client I like to work with, because the more a client knows about what is going on, the more likely it is they will see the complexity of the decisions that need to be made in their bike fitting. This is a client who will see the process, as we do it, for what it is -- a service that is one of a kind and geared toward only making their bike work better for them.
So Dave is fit, but like all human beings who live on the modern world of driving cars, computer work, and tools that do our work for us, he has a few imbalances:
+ one leg is stronger and more coordinated than the other
+ he is asymmetric through his shoulder motion and strength
+ he has a small twist originating in his lumbar spine
+ somewhat weak intrinsic foot muscles and resultant pronation tendencies, etc. etc.
When you start to list all these things out, you get the impression that he's a wreck -- not so. This is very typical of what I find in my initial body assessment (he actually has fewer and smaller issues than many).
He has some neck discomfort when on the bike for a while; recovering from some knee pain, of the tendinitis sort, and some back pain on occasion as well.
Here are his first two Retul files that we took:
He had his (very well appointed and beautifully built) Felt B2 set up in the more relaxed seatpost position, and had also put on a stem of equal length to the original it came with, but now with more rise to raise the aerobars up some.
Many times I see people where their pedal stroke clearly has a hitch or hesitation in it, but Dave has spent too much time on his bike for that. His issue was more subtle. After doing this for ten years, I can see that his pedal stroke, while very practiced and relatively smooth, seems slightly disjointed. It's almost as if his upper and lower body are working independently of each other, rather than together.
After looking at the Retul files, it was clear his left side was getting sacrificed -- it had more lateral knee travel and the knee tracked at about an 8 degree angle, not to mention more hip motion.
I was more concerned with his angles at his elbow and shoulder, however. The angle at his elbows was almost 100 degrees and his shoulders were open and rather stretched out (the Retul takes two different shoulder or "armpit" angles -- to the elbow and the wrist). When your shoulders are stretched out like that a few things happen. First, your lats (latissimus dorsi) are lengthened and if they are pulled too far, they can exert a force on the lower thoracic and lumbar spine where they originate. This decreases the mobility of the lower half of the spine. Also, the shoulder blades, or scapulae have to move with our shoulder joints, so when the shoulder is flexed excessively, the shoulder blades must protract (move outward), thereby stretching the muscles that attach the shoulder blade to the mid-thoracic spine. Just like with the lats, this decreases the mobility of this portion of the spine. Take a look at this picture and you can see this with the "round-ness" of his back.
Also, note where the elbow and the shoulder dot are located, with the elbow being in front. In the aero position, we would like to support ourselves (especially the upper body) with as little active muscular input as possible, and if we need to use muscles, we'd want to use respiratory muscles (muscles we use in breathing) as little as possible. Often, when the elbow and shoulder have this relative position we are using excessive upper body muscular force to hold us up, rather than just "resting" on our skeletal support.
Corrections:
So to fix things I wanted to first address the upper body, lower body disconnect I was seeing. Dave's Felt was built with a two position seatpost, and he originally had it in the further back, relaxed seat angle position, so we changed it to the steeper configuration. We also made sure the seat was level (a huge mistake that triathletes make with respect to saddle position is to nose-down the saddle to reduce pressure on their perineum. This just causes you to bear more weight on your upper body as you constantly slip off the front of the saddle -- I always think of it as "tripod-ing" on the bike) and made a small seat height adjustment to accommodate the now-level seat.
This fit is proof that a higher handlebar position isn't always more "relaxed" or comfortable. Because we were rotating his hips forward and up over the bottom bracket, and because Dave has good fitness and strength in the right areas, we were able to lower his handlebars and in the process we put his upper body biomechanically where it needed to go. We improved his power, we reduced the muscular requirement to hold himself on his bike (he will have a front heavy sensation on the bike for a while since we brought his center of gravity forward on the bike, but this will decrease as his body begins to proprioceptively "get it") and improved his aerodynamics all with just two changes.
His left side was being sacrificed, as I said before, and we needed to get it in the game. It is less coordinated and not as strong, so we put a couple of forefoot wedges in his left shoe to improve that foot's contact with the pedal. Over time, this correction, will begin to re-train the muscles in the left leg and hip to get through the pedal stroke without inhibiting the right side.
Here is an after photo to compare with the previous one:
Look at how much more relaxed his spine looks. His elbows are tucked underneath him nicely, and because we've taken stress off the muscles supporting the shoulder blades (which incidentally also attach to the neck) he is able to move his head easier from side to side and look up. Go back and look at the first photo -- see the impression that his shoulder blade makes under the skin. No such impression on the after picture because that shoulder blade is resting more comfortably on the back of the rib cage rather than on the side of it.
The position is definitely more compact, and will take some adjustment time -- but luckily Dave is in a step-down period of his training, so he'll benefit from some moderate rides to allow his body to adapt. We may still make some minor tweaks in the near future, but I think he now has a good long distance tri bike position to keep him powerful for a full 112 miles. (But I'll let Dave himself comment here on how the fit is working, if he'd like)
The Retul travels quite well. It packs away neatly into (what I am told is) a gun case. The most difficult thing to plan for is to have enough parts and equipment for as many possible fitting changes as possible. Carrying a few dozen stems of various sizes is no problem -- it's the handlebars (because of their size), and seatposts (too many different diameters) that are tough.
So anyway, I was in beautiful Basalt, Colorado this Saturday and Sunday to see a number of clients. I ended up doing about 11 hours worth of fittings on Saturday and another 3 hours on Sunday, so you can begin to get an idea of why I am "recovering".
Lots of very nice people, ages ranging from in their 30's to the upper 70's. Yep, you read that right. There are some very fit folks out in this part of the country.
One client that was a lot of fun was Dave C. He is an avid long distance triathlete; he just finished a 70.3 in Boise the week before. He is very fit, motivated, and attentive -- your basic Type A triathlete. He listened very well and asked a lot of good questions - exactly the type of client I like to work with, because the more a client knows about what is going on, the more likely it is they will see the complexity of the decisions that need to be made in their bike fitting. This is a client who will see the process, as we do it, for what it is -- a service that is one of a kind and geared toward only making their bike work better for them.
So Dave is fit, but like all human beings who live on the modern world of driving cars, computer work, and tools that do our work for us, he has a few imbalances:
+ one leg is stronger and more coordinated than the other
+ he is asymmetric through his shoulder motion and strength
+ he has a small twist originating in his lumbar spine
+ somewhat weak intrinsic foot muscles and resultant pronation tendencies, etc. etc.
When you start to list all these things out, you get the impression that he's a wreck -- not so. This is very typical of what I find in my initial body assessment (he actually has fewer and smaller issues than many).
He has some neck discomfort when on the bike for a while; recovering from some knee pain, of the tendinitis sort, and some back pain on occasion as well.
Here are his first two Retul files that we took:
He had his (very well appointed and beautifully built) Felt B2 set up in the more relaxed seatpost position, and had also put on a stem of equal length to the original it came with, but now with more rise to raise the aerobars up some.
Many times I see people where their pedal stroke clearly has a hitch or hesitation in it, but Dave has spent too much time on his bike for that. His issue was more subtle. After doing this for ten years, I can see that his pedal stroke, while very practiced and relatively smooth, seems slightly disjointed. It's almost as if his upper and lower body are working independently of each other, rather than together.
After looking at the Retul files, it was clear his left side was getting sacrificed -- it had more lateral knee travel and the knee tracked at about an 8 degree angle, not to mention more hip motion.
I was more concerned with his angles at his elbow and shoulder, however. The angle at his elbows was almost 100 degrees and his shoulders were open and rather stretched out (the Retul takes two different shoulder or "armpit" angles -- to the elbow and the wrist). When your shoulders are stretched out like that a few things happen. First, your lats (latissimus dorsi) are lengthened and if they are pulled too far, they can exert a force on the lower thoracic and lumbar spine where they originate. This decreases the mobility of the lower half of the spine. Also, the shoulder blades, or scapulae have to move with our shoulder joints, so when the shoulder is flexed excessively, the shoulder blades must protract (move outward), thereby stretching the muscles that attach the shoulder blade to the mid-thoracic spine. Just like with the lats, this decreases the mobility of this portion of the spine. Take a look at this picture and you can see this with the "round-ness" of his back.
Also, note where the elbow and the shoulder dot are located, with the elbow being in front. In the aero position, we would like to support ourselves (especially the upper body) with as little active muscular input as possible, and if we need to use muscles, we'd want to use respiratory muscles (muscles we use in breathing) as little as possible. Often, when the elbow and shoulder have this relative position we are using excessive upper body muscular force to hold us up, rather than just "resting" on our skeletal support.
Corrections:
So to fix things I wanted to first address the upper body, lower body disconnect I was seeing. Dave's Felt was built with a two position seatpost, and he originally had it in the further back, relaxed seat angle position, so we changed it to the steeper configuration. We also made sure the seat was level (a huge mistake that triathletes make with respect to saddle position is to nose-down the saddle to reduce pressure on their perineum. This just causes you to bear more weight on your upper body as you constantly slip off the front of the saddle -- I always think of it as "tripod-ing" on the bike) and made a small seat height adjustment to accommodate the now-level seat.
This fit is proof that a higher handlebar position isn't always more "relaxed" or comfortable. Because we were rotating his hips forward and up over the bottom bracket, and because Dave has good fitness and strength in the right areas, we were able to lower his handlebars and in the process we put his upper body biomechanically where it needed to go. We improved his power, we reduced the muscular requirement to hold himself on his bike (he will have a front heavy sensation on the bike for a while since we brought his center of gravity forward on the bike, but this will decrease as his body begins to proprioceptively "get it") and improved his aerodynamics all with just two changes.
His left side was being sacrificed, as I said before, and we needed to get it in the game. It is less coordinated and not as strong, so we put a couple of forefoot wedges in his left shoe to improve that foot's contact with the pedal. Over time, this correction, will begin to re-train the muscles in the left leg and hip to get through the pedal stroke without inhibiting the right side.
Here is an after photo to compare with the previous one:
Look at how much more relaxed his spine looks. His elbows are tucked underneath him nicely, and because we've taken stress off the muscles supporting the shoulder blades (which incidentally also attach to the neck) he is able to move his head easier from side to side and look up. Go back and look at the first photo -- see the impression that his shoulder blade makes under the skin. No such impression on the after picture because that shoulder blade is resting more comfortably on the back of the rib cage rather than on the side of it.
The position is definitely more compact, and will take some adjustment time -- but luckily Dave is in a step-down period of his training, so he'll benefit from some moderate rides to allow his body to adapt. We may still make some minor tweaks in the near future, but I think he now has a good long distance tri bike position to keep him powerful for a full 112 miles. (But I'll let Dave himself comment here on how the fit is working, if he'd like)
Monday, June 1, 2009
Front of the knee pain, but first....
Someone asked me a good question the other day:
By writing this blog, aren't you worried about giving away the bike fitting secrets that you've learned and inceasing your competition?
I guess I never really thought about it that way. To me, it's like an architect being worried that by explaining to his clients how their house is drawn up, then they'll use that information to finish the project on their own. There is just too much to know, and most folks, while they may find the information interesting (and I hope everyone does -- I know it can be a bit dry, but we are all nerdy cyclists at heart, and this is the stuff we love to read about), it's not likely anyone is going to be able to read my blog and open up shop on their own based solely on this information. I think it's important that there are practitioners of bike fitting out there that are taking the process more seriously, and treating it as it should be treated -- a very complex, biomechanics-based area of study, and not just a bike shop service.
So now onto the technical stuff.
One of the most common problems I see on the bike is frontal knee pain. Sometimes it is a force issue (just pushing too big of a gear for too long)
(brief diversion)
****I frequently get front of the knee pain (on the right) as I get back into riding shape. My seat height is good, I sit fairly straight on the saddle (see HERE); so what's the problem? As you can see from some of the biofeedback studies we did HERE, when I am not fit, my pedal stroke is not very efficient and I tend to be right leg dominant (like most of the population) AND I am very quadricep dominant when re-learning my pedal stroke. I am just pushing too much with my right leg and the choppy nature of my pedal stroke is requiring more of my quads, so my kneecap and patellar tendon are under tremendous strain.****
(and we're back...)
, but it can also be a patellar tracking issue, IT Band problems (and, incidentally, patellar tracking and IT band sometimes are not mutually exclusive), increased patellar compression/chondromalacia, or even referred or radicular lumbar pain.
The common "fix" you hear about with front of the knee pain is that your saddle is too low and raising it is necessary. Many times this is the case, but it becomes less likely when the pain is only on one side. (If you have a leg length discrepancy or your pelvis sits skewed on the saddle, the seat height may be too low for one leg and perfect or too high for the other leg; in this case you have to figure out why you aren't sitting symmetrically on the saddle first, and fix that)
So if your seat height is okay, where to next? One often overlooked area is how we toe in and toe out. In much of the research it is called inversion (toeing in) and eversion (toeing out) which on the bike is a little different than the motion we refer to as inversion and eversion in biomechanics. On the bike because of how the cleat fastens to the pedal the motion is truly just toeing in and toeing out, but in biomechanics-speak, the toes go in (medially) with inversion, but the bottom of the foot actually points in (medially) as well; opposite for eversion.
Generally when we invert our feet on the bike it drives the knee and increases what's called a valgus force on the knee (valgus = think of looking at the knee straight on and a force presses on the knee from the outside and forces it into a "knock-kneed" position). Conversely, when we evert our foot, we increase the varus force through the knee (think "bow-legged"). This valgus force at the knee essentially takes the ever-important medial quads out of the equation more. These medial quads (vastus medialis and a bit less correctly, VMO) are important because they need to be adequately active to keep the patella in between the two notches at the bottom of the femur. If the patella is not lined up then the underside of it gets dragged against the lateral notch and can cause cartilage damage and pain. The valgus force at the knee puts the medial quads at a mechanical disadvantage. Everting the foot a small amount may reduce this valgus force, and consequently allow the medial quads do their job and/or aid in patellar tracking.
All of this can be read in a great article by Gregersen, Hull, and Hakansson in the June 2006 Journal of Biomechanical Engineering:
How Changing the Inversion/Eversion Foot Angle Affects the Nondriving Intersegmental Knee Moments and the Relative Activation of the Vastii Muscles in Cycling by Gregersen CS, Hull ML, Hakansson NA
I have many clients who have front of the knee pain and the simple act of toeing their foot out (eversion) sometimes helps. Some clients can feel it "unlock" or "unload" their knee almost immediately.
So this is a good option to try if you are at a loss for your knee pain. Just keep in mind that like a lot of things in bike fitting, very tiny corrections are necessary most of the time. Also, remember that when you are changing cleat/foot position, you have to think in opposites: if you want to toe your foot out, you have to toe the cleat in.
But keep in mind that the consequences of toeing out (decreasing the "knock-kneed" force etc.) is what often, but not always, happens. Because we are all just experiments of one we cannot take this as the only consequence. I have, in fact, had some clients who show signs of an increased valgus force about the knee when they toe out. In at least one case it was due to some odd midfoot mechanics, but this cannot be discounted -- there are other people out their with these same mechanics and there are most certainly other movement asymmetries that could cause this eversion/varus relationship to break down as well.
By writing this blog, aren't you worried about giving away the bike fitting secrets that you've learned and inceasing your competition?
I guess I never really thought about it that way. To me, it's like an architect being worried that by explaining to his clients how their house is drawn up, then they'll use that information to finish the project on their own. There is just too much to know, and most folks, while they may find the information interesting (and I hope everyone does -- I know it can be a bit dry, but we are all nerdy cyclists at heart, and this is the stuff we love to read about), it's not likely anyone is going to be able to read my blog and open up shop on their own based solely on this information. I think it's important that there are practitioners of bike fitting out there that are taking the process more seriously, and treating it as it should be treated -- a very complex, biomechanics-based area of study, and not just a bike shop service.
So now onto the technical stuff.
One of the most common problems I see on the bike is frontal knee pain. Sometimes it is a force issue (just pushing too big of a gear for too long)
(brief diversion)
****I frequently get front of the knee pain (on the right) as I get back into riding shape. My seat height is good, I sit fairly straight on the saddle (see HERE); so what's the problem? As you can see from some of the biofeedback studies we did HERE, when I am not fit, my pedal stroke is not very efficient and I tend to be right leg dominant (like most of the population) AND I am very quadricep dominant when re-learning my pedal stroke. I am just pushing too much with my right leg and the choppy nature of my pedal stroke is requiring more of my quads, so my kneecap and patellar tendon are under tremendous strain.****
(and we're back...)
, but it can also be a patellar tracking issue, IT Band problems (and, incidentally, patellar tracking and IT band sometimes are not mutually exclusive), increased patellar compression/chondromalacia, or even referred or radicular lumbar pain.
The common "fix" you hear about with front of the knee pain is that your saddle is too low and raising it is necessary. Many times this is the case, but it becomes less likely when the pain is only on one side. (If you have a leg length discrepancy or your pelvis sits skewed on the saddle, the seat height may be too low for one leg and perfect or too high for the other leg; in this case you have to figure out why you aren't sitting symmetrically on the saddle first, and fix that)
So if your seat height is okay, where to next? One often overlooked area is how we toe in and toe out. In much of the research it is called inversion (toeing in) and eversion (toeing out) which on the bike is a little different than the motion we refer to as inversion and eversion in biomechanics. On the bike because of how the cleat fastens to the pedal the motion is truly just toeing in and toeing out, but in biomechanics-speak, the toes go in (medially) with inversion, but the bottom of the foot actually points in (medially) as well; opposite for eversion.
Generally when we invert our feet on the bike it drives the knee and increases what's called a valgus force on the knee (valgus = think of looking at the knee straight on and a force presses on the knee from the outside and forces it into a "knock-kneed" position). Conversely, when we evert our foot, we increase the varus force through the knee (think "bow-legged"). This valgus force at the knee essentially takes the ever-important medial quads out of the equation more. These medial quads (vastus medialis and a bit less correctly, VMO) are important because they need to be adequately active to keep the patella in between the two notches at the bottom of the femur. If the patella is not lined up then the underside of it gets dragged against the lateral notch and can cause cartilage damage and pain. The valgus force at the knee puts the medial quads at a mechanical disadvantage. Everting the foot a small amount may reduce this valgus force, and consequently allow the medial quads do their job and/or aid in patellar tracking.
All of this can be read in a great article by Gregersen, Hull, and Hakansson in the June 2006 Journal of Biomechanical Engineering:
How Changing the Inversion/Eversion Foot Angle Affects the Nondriving Intersegmental Knee Moments and the Relative Activation of the Vastii Muscles in Cycling by Gregersen CS, Hull ML, Hakansson NA
I have many clients who have front of the knee pain and the simple act of toeing their foot out (eversion) sometimes helps. Some clients can feel it "unlock" or "unload" their knee almost immediately.
So this is a good option to try if you are at a loss for your knee pain. Just keep in mind that like a lot of things in bike fitting, very tiny corrections are necessary most of the time. Also, remember that when you are changing cleat/foot position, you have to think in opposites: if you want to toe your foot out, you have to toe the cleat in.
But keep in mind that the consequences of toeing out (decreasing the "knock-kneed" force etc.) is what often, but not always, happens. Because we are all just experiments of one we cannot take this as the only consequence. I have, in fact, had some clients who show signs of an increased valgus force about the knee when they toe out. In at least one case it was due to some odd midfoot mechanics, but this cannot be discounted -- there are other people out their with these same mechanics and there are most certainly other movement asymmetries that could cause this eversion/varus relationship to break down as well.
Thursday, May 28, 2009
Retul Bike fits
If you've read my blog before you know that I use the Retul system of motion capture (www.retul.com). I get a lot of questions about it -- and a lot of business frankly.
I often hear,
"Wow, that must really make the fittings easier, huh?"
After using the system for a while now I finally have an answer to that. Does it make the fittings easier? The short answer is "No", unequivocally, it does not make the process simpler.
Blasphemy, right? Retul is definitely the most influential technology to come into bike fitting in, well, maybe forever, and here I am dissing it?
Well, I don't think it is a "knock" on the system because it doesn't make bike fits easier. People and companies (i.e. Specialized) have been taking a reductionist approach to bike fitting and it has done nothing positive to the process. The *Fit Kit", *BG Fit*, *Wobblenaught* among others have tried to take this very complex process and turn it into a nice neat, packaged "revenue driver" that every bike shop in the world can become an expert in.
I think it is actually a tribute to the system that it doesn't "dumb down" the process. It in no way tells you what you should do to take corrective action for the cyclist - it just provides a lot of very accurate data about the cyclist's mechanics.
For each of the parameters it measures -- for instance the frontal angle a rider's knee tracks at relative to the vertical, called Knee Travel Tilt -- Retul provides a range of normal limits that each one, in an ideal situation, should stay within.
The difficulty lies in the shear amount of data. If you focus on one measurement and make changes to the rider's position to "fix" just that one measurement, often other measurements that are also a problem, don't change or get worse.
So, no, my bike fitting process has not gotten simpler. But I'm not the least bit disappointed. Actually this has been the most productive and fun year for me with bike fittings (in my 12 years as a physical therapist).
My bike fittings have gotten better, and that's the important part. The Retul system has allowed a level of accuracy and confidence that is hard to beat. Plus when it comes to bike fitting, "simple" isn't always the best solution.
But "better" is.
Wednesday, May 6, 2009
Musings about credentials for bike fitting
I get asked a lot by people out of state, My next trip to Colorado, I'm going to come in for a fitting. But do you know anyone in my area that can do a good bike fitting?
That's a hard one. I don't have a lot of names that I trust implicitly to do a comprehensive bike fitting. I think by endorsing someone, I am putting my reputation in their hands. Not many people out there I would do that for. There are a few, and if you live in their territory I will let you know who they are.
I am pretty particular about my fitting process, and I think too many shops out there are relying on the WOW factor of their gadgets, and their client's....I don't want to say ignorance, because that seems harsh -- after all, bike shops should know bikes, and many riders just don't have the inclination to learn about their bike and that's just fine. That's why you have a bike shop! But many clients do trust that their bike shop knows all things bike. Bike fit included.
Unfortunately that is just not the case. Most bike shops know bikes. They should. "The bike" is the easy part in the equation of bike fitting. Truly, anyone with a little time and motivation can learn enough in a short time to WORK in a bike shop. Every year thousands of high school and college age kids begin working at a bike shop and in pretty short order they are assembling and repairing bikes right alongside the "career mechanic." There are bike mechanic schools out there, but very few people building bikes in the United States are attending them. I think that's a shame. It doesn't say much for the person who is a career mechanic and it certainly doesn't help them earn a better living. When you have a profession that is unregulated, unlicensed, and requires no formal training, then you just don't have to pay those people that much. (and by "you" I mean the market in general).
Side note: A very experienced and skilled bike mechanic is an amazing thing. They are such a wealth of bike knowledge that at times is indispensable. I want to be clear how much I respect the true experts of this discipline. My point is that you likely won't go to you bike mechanic for a bike fitting just as you wouldn't go to your bike fitter for a question about derailleur actuation ratios or air chamber pressures on your rear shock.
So to get back to my point, the bike is the easy part to learn about. The variables are few and relatively fixed.
The human body, however, is exactly the opposite. It's not likely that you are going to be able to "apprentice" with a doctor, or a PT, or an exercise physiologist, and learn their trade in a few weeks or months. There are too many variables, and what's more, often these variables are hidden under layers of skin, muscle and fascia, so an intimate knowledge of their location, function, and physiology is necessary. (Again, in contrast, most of a bike's parts are easily seen and quantified.)
So you can see how it would be easy for a bike shop to alter your bike for you, but difficult for them to explain to you why you need it changed.
Some bike shops will say that they have been doing bike fits long enough that they know the 10 most common syndromes associated with ill-fitting bikes, and that that covers them for most cyclists. I don't know about you, but I don't want to pay someone hundreds of dollars in a fitting fee and more money for new equipment if they don't KNOW that it is going to help. In the last ten years I have done more fittings than most bike shops in the country, and I would estimate that fully 25-35% had some combination of mechanical issues that manifested themselves on the bike in a way I had not seen before, and about 50% fell outside of what I would consider to be the "10 most common bike fit issues". In these situations I had to rely on my education and experience with the biomechanics of the human body.
To understand all these differences it takes time and lots and lots of clients -- I call it the "Malcolm Gladwell Effect". In his fantastic book Outliers: The Story of Success, he explains that thorough research has come up with a metric for understanding why some people become experts at the top of the field, and the general threshold for this is 10,000 hours of practice. Bill Gates began programming as a "tween" at a time when only a handful of people on the planet even had access to a computer to program on. Michael Jordan out-worked all his competitors by spending hours and hours EVERY single day to improve his skills.
Similarly, a bike fitter only gets to be an expert when they spend every day working their diagnostic muscles. This is where physical therapists and other clinicians have a huge advantage over bike shop employees and other fitters -- we get to practice and flex those same mental muscles every day, even outside of our bike fittings as we treat 5, 10, 15 clients a day. The treatments are different but the "work" and knowledge gained and reinforced is the same. Typically even a busy bike fitter may see 5-10 clients a week -- this would be an awfully slow way to learn the craft.
This also brings up a point that bike shops are in the business of selling bikes and bike parts. Unfortunately with the boom in the number of shops offering "fitting services" many did so because their industry advisors were telling them how many replacement parts and accessories they could sell.
I'm not trying to make people paranoid or distrustful of their LBS. Fact is I think there are plenty of shops out there TRYING to do the right thing. I just think that they in over their head with the complexity of many bike fits.
The difficulty lies in the fact that many people experience discomfort or a decrease in power and if you just LOOK at them, they appear to be set up in a very typical road position.
Example:
I had a client recently come in for a fitting on a bike she had bought a few months before. She hadn't ridden it much because she bought at the end of the fall and she was not a cold weather rider. She got a "good deal" on the bike. The young salesperson helping her helped her find the bike, they set her up on a trainer and she pedaled the bike for 2 or 3 minutes. It felt "Okay" (her words) while she was on the trainer, but to be sure, they stopped the lone "bike fit guru" (who is also the head mechanic and part owner) as he was rushing across the shop in search of a part for another client, to have a look. He watched her sit on the bike and pedal for 5 or 6 pedal strokes and declared, "Looks good." And he rushed off. Sometimes the shop (but really the client) might get lucky and everything might actually BE good.
In this case, however, once she spent more than 5 or 10 minutes on the bike it was clear she wasn't comfortable. So they came to see me, and this is when she had her second chance to get lucky -- the bike could be the right size but just need some adjustments - maybe we could "make it work". Unfortunately, the frame was the wrong size and to have an appropriate reach on the bike she'd need to have the seat all the way forward on the rails (with a 0 degree setback post) and a 60 mm stem -- definitely not ideal.
So what is the lesson with that story? Again, not that you should distrust your LBS, because I think this shop was TRYING to do the right thing (admittedly a bit half a**ed). They are just not very good at it.
Luckily there are more and more bike fitters that have education in anatomy, biomechanics etc. AND have years of experience applying this knowledge. These two things are incredibly important and you should do some digging to find out about any bike fitter you intend to visit.
That's a hard one. I don't have a lot of names that I trust implicitly to do a comprehensive bike fitting. I think by endorsing someone, I am putting my reputation in their hands. Not many people out there I would do that for. There are a few, and if you live in their territory I will let you know who they are.
I am pretty particular about my fitting process, and I think too many shops out there are relying on the WOW factor of their gadgets, and their client's....I don't want to say ignorance, because that seems harsh -- after all, bike shops should know bikes, and many riders just don't have the inclination to learn about their bike and that's just fine. That's why you have a bike shop! But many clients do trust that their bike shop knows all things bike. Bike fit included.
Unfortunately that is just not the case. Most bike shops know bikes. They should. "The bike" is the easy part in the equation of bike fitting. Truly, anyone with a little time and motivation can learn enough in a short time to WORK in a bike shop. Every year thousands of high school and college age kids begin working at a bike shop and in pretty short order they are assembling and repairing bikes right alongside the "career mechanic." There are bike mechanic schools out there, but very few people building bikes in the United States are attending them. I think that's a shame. It doesn't say much for the person who is a career mechanic and it certainly doesn't help them earn a better living. When you have a profession that is unregulated, unlicensed, and requires no formal training, then you just don't have to pay those people that much. (and by "you" I mean the market in general).
Side note: A very experienced and skilled bike mechanic is an amazing thing. They are such a wealth of bike knowledge that at times is indispensable. I want to be clear how much I respect the true experts of this discipline. My point is that you likely won't go to you bike mechanic for a bike fitting just as you wouldn't go to your bike fitter for a question about derailleur actuation ratios or air chamber pressures on your rear shock.
So to get back to my point, the bike is the easy part to learn about. The variables are few and relatively fixed.
The human body, however, is exactly the opposite. It's not likely that you are going to be able to "apprentice" with a doctor, or a PT, or an exercise physiologist, and learn their trade in a few weeks or months. There are too many variables, and what's more, often these variables are hidden under layers of skin, muscle and fascia, so an intimate knowledge of their location, function, and physiology is necessary. (Again, in contrast, most of a bike's parts are easily seen and quantified.)
So you can see how it would be easy for a bike shop to alter your bike for you, but difficult for them to explain to you why you need it changed.
Some bike shops will say that they have been doing bike fits long enough that they know the 10 most common syndromes associated with ill-fitting bikes, and that that covers them for most cyclists. I don't know about you, but I don't want to pay someone hundreds of dollars in a fitting fee and more money for new equipment if they don't KNOW that it is going to help. In the last ten years I have done more fittings than most bike shops in the country, and I would estimate that fully 25-35% had some combination of mechanical issues that manifested themselves on the bike in a way I had not seen before, and about 50% fell outside of what I would consider to be the "10 most common bike fit issues". In these situations I had to rely on my education and experience with the biomechanics of the human body.
To understand all these differences it takes time and lots and lots of clients -- I call it the "Malcolm Gladwell Effect". In his fantastic book Outliers: The Story of Success, he explains that thorough research has come up with a metric for understanding why some people become experts at the top of the field, and the general threshold for this is 10,000 hours of practice. Bill Gates began programming as a "tween" at a time when only a handful of people on the planet even had access to a computer to program on. Michael Jordan out-worked all his competitors by spending hours and hours EVERY single day to improve his skills.
Similarly, a bike fitter only gets to be an expert when they spend every day working their diagnostic muscles. This is where physical therapists and other clinicians have a huge advantage over bike shop employees and other fitters -- we get to practice and flex those same mental muscles every day, even outside of our bike fittings as we treat 5, 10, 15 clients a day. The treatments are different but the "work" and knowledge gained and reinforced is the same. Typically even a busy bike fitter may see 5-10 clients a week -- this would be an awfully slow way to learn the craft.
This also brings up a point that bike shops are in the business of selling bikes and bike parts. Unfortunately with the boom in the number of shops offering "fitting services" many did so because their industry advisors were telling them how many replacement parts and accessories they could sell.
I'm not trying to make people paranoid or distrustful of their LBS. Fact is I think there are plenty of shops out there TRYING to do the right thing. I just think that they in over their head with the complexity of many bike fits.
The difficulty lies in the fact that many people experience discomfort or a decrease in power and if you just LOOK at them, they appear to be set up in a very typical road position.
Example:
I had a client recently come in for a fitting on a bike she had bought a few months before. She hadn't ridden it much because she bought at the end of the fall and she was not a cold weather rider. She got a "good deal" on the bike. The young salesperson helping her helped her find the bike, they set her up on a trainer and she pedaled the bike for 2 or 3 minutes. It felt "Okay" (her words) while she was on the trainer, but to be sure, they stopped the lone "bike fit guru" (who is also the head mechanic and part owner) as he was rushing across the shop in search of a part for another client, to have a look. He watched her sit on the bike and pedal for 5 or 6 pedal strokes and declared, "Looks good." And he rushed off. Sometimes the shop (but really the client) might get lucky and everything might actually BE good.
In this case, however, once she spent more than 5 or 10 minutes on the bike it was clear she wasn't comfortable. So they came to see me, and this is when she had her second chance to get lucky -- the bike could be the right size but just need some adjustments - maybe we could "make it work". Unfortunately, the frame was the wrong size and to have an appropriate reach on the bike she'd need to have the seat all the way forward on the rails (with a 0 degree setback post) and a 60 mm stem -- definitely not ideal.
So what is the lesson with that story? Again, not that you should distrust your LBS, because I think this shop was TRYING to do the right thing (admittedly a bit half a**ed). They are just not very good at it.
Luckily there are more and more bike fitters that have education in anatomy, biomechanics etc. AND have years of experience applying this knowledge. These two things are incredibly important and you should do some digging to find out about any bike fitter you intend to visit.
Saturday, April 18, 2009
Guru Sidero - steel road bike *Now on Sale*
So this is another Studio demo/floor bike. I decided to try out the new steel offering from Guru, and I must say, it turned out great.
I pieced the build kit together to match (as you can see) the bike's paint, and the result is striking, I think.
I order the demo bikes with my own Studio signature geometry -- basically I tweak the stock geometry provided by Guru so that it fits the cyclist(s) I think would be interested in such a bike.
Head tube = 14 cm
Effective Top Tube = 50 cm
Standover = ~73 cm
The bike is built with SRAM Force throughout, Ritchey Pro Alloy kit, and Fulcrum Racing 7 wheels.
The Fulcrum wheels were a nice addition. This year they changed the wheel from having red accents on the decals to the hubs, rims, and nipples all being fully anodized red. They really make the look of the whole bike.
I have again used the SRAM SuperLight bar tape -- this time in red -- it just has a great feel to it and it wears extremely well. I have two clients that I built bikes for a year ago. Just did a check-up on their rides and the tape still looks brand new; that is considering a lot of miles and a couple of trips overseas with the bikes.
This complete bike, for full custom geometry, is $3950 with a Force group and about $3300 with a SRAM Rival set up.
I think this is a really great pricepoint for a non-pricepoint bike.
Monday, April 13, 2009
What are our muscles really doing when we pedal?
So my fit Studio is in a Physical Therapy clinic, which makes sense, because I am a practicing PT. My co-worker, and owner of the PT clinic, Rik is trained in a new biofeedback system. Biofeedback uses electrode patches placed over the muscles to determine how much these muscles are working -- how much, how soon they kick in, how long they stay "on", how they "turn off", etc. As you can imagine, this is highly useful with our clients.
So we decided to test a few cyclists and see what we came up with. We could simultaneously use the Retul, to pick up movement imbalances and then cross reference with the biofeedback to try and figure out what the muscles on each side of the body were and were not doing. We can even then use the biofeedback while the person pedals to "train" them what activating certain muscles at specific times "feels" like to help correct the underlying muscular problem.
First we have to test as many people as we can, to start to figure out common muscular patterns. Hopefully we can figure out what is "normal" but if my line of work has taught me anything, it's that there aren't many "normals" out there. That's why I think it's more likely we'll find common motor patterns that may not be symmetric, amongst many athletes.
Subject #1 : Me, 33 y/o, male, 5'10", 175#
I have a fairly symmetrical pedal stroke. If I had to guess I would think that I am a bit right side dominant, and probably scoot off the right side of my saddle because of it. But we don't have to guess, because here is a right and left Retul file from a recent test on myself:
Not bad.
Next was to hook up the biofeedback. This involves placing small sticker-like electrodes strategically over the muscles you want to test. Wires snap to the electrodes and run to a little processing unit that reminds me of a car radar detector.
The "radar detector" talks to the laptop via a BlueTooth connection -- the setup is pretty slick.
The software that Rik uses seems to have endless choices on how to set up the display screens so that you can simultaneously see what the
different muscle groups are doing.
When I was hooked up to the biofeedback unit we decided to test vastus lateralis (VL) (the quadricep or thigh muscle on the outside of the
leg -- this tends to be very pronounced in cyclists), vastus medialis (VM) (quad to the inside just above the knee, and the hamstring. We tested these muscles on both legs, so we could compare how much more the right or the left lateral quad was working, but we could also compare how much and when the medial vs. the lateral quad did work on the same side. We could also compare this to how the hamstrings worked.
We tested all three muscle group -- VL, VM, hamstring -- on both legs, of course at 150 watts and at 215 watts.
The printout from the biofeedback looks like this:
Below are the printouts bottom half of the page. The colum to focus on is the one that says "Mean" -- they are basically the normalized mA that the electrodes pick up from each of the
muscles.
There are four sets of data: comparing VMO/VL at 150 Watts, VMO/VL at 215 watts, VMO/hamstring at 150 watts, and VMO/hamstring at 215 watts.
VM/VL @ 150 watts
VM/VL @ 215 watts
VM/hamstring @150 watts
VM/hamstring @ 215 watts
As you can see from the sheets, my right quads (medial and lateral) both work more than the left at all wattages. But when I increased from 150 watts to 215 watts my left quads increased their activity 18% while the right increased 23% (VL) and 29% (VM).
The next round of tests, comparing the VM to the hamstrings on both sides confirmed an 18% and 29% increase respectively for left and right for the VM when going from 150 watts to 215 watts. The hamstrings, which overall, were not very active increased 31% on the right and 38% on the left; this increase on the left might make one think that the left "evens out" at higher wattage, but I think it is still a bigger issue: the right hamstring was more active at 150 than the left was at 215. The fact that the starting point for the left hamstring was so bad made it's improvement seem more drastic.
What did we learn?
I think this first round of tests is encouraging and shows that we can, with good effect correlate what our mechanics are like (from the Retul data) and what the muscles themselves are doing. We should be able to explain why a cyclist may pedal with an asymmetry and whether it is due to a poor motor plan or if it has more structural origins.
I think we can safely say that one of the main reason that I sit a bit skewed on the saddle is because my pedal stroke's motor plan has a significant emphasis on my dominant right leg. I think with more data we will see that my current pedal stroke is poor in the efficiency category because I have not been riding as much lately and I am getting a very small contribution from the hamstring muscles. I am not "pedaling ellipses" but rather more up and down (and definitely more down than up).
Theory
I have a theory as well about the activation of our quadriceps when we pedal that has to do with left and right efficiency. I believe I am more coordinated (because pedaling is a coordinated task) on my right leg -- it's clear my hamstring are more active on the right and help to smooth out my pedal stroke. I am also more skilled at one leg pedaling drills on my right leg -- less "clunking" through the stroke and better cadence.
I think, based on some of the muscle activation graphs that I saw for me (and they would have been difficult to post here -- sorry), that our more efficient leg will see the quads activate later and relax earlier than the non-dominant side. So the non-dominant side will have a more consistent or longer activation patter than the dominant side.
This to me seemed counter-intuitive at first, but after some thought I realized that because my dominant side hamstring were activating better, they would inhibit the quads sooner since the load was now taken up by this new group of muscles -- the more "normal" or efficient pedal stroke. The dominant side could more accurately and quickly kick itself on and off in time with my cadence and when it kicked on it could fire more motor units more quickly. I think this would have implications, of course, on negative torque values (when your quads are still pushing down on the pedal after it has passed the dead bottom center position and therefore exerting negative torque or power) but also in terms of fatigue. The non-dominant quad is staying "on" longer, even when it shouldn't and wastes unnecessary effort -- it fatigues quicker even though it is adding less to the overall workload.
Anyway, I should have more data coming this weekend and next week with a few more guinea pigs so stay tuned.
Thursday, April 9, 2009
uber-commuter
I had to post these pictures. I don't haul this much normally, of course, but today I had to bring a number of things in to work. This is why I love the Surly Big Dummy.
I had to get all of this onto my bike (well I could have driven, but that would be cheating):
And here is how I did it:
I love this bike
Wednesday, April 8, 2009
Talkin' bike seats
I mentioned in my last post that, for the average woman, and ideal seat design would be wide in the back to support the wider ischial tuberosities, but then needs to quickly narrow to avoid compressing the tissues distal and lateral to the sit bones.
This narrower space between the femur and sit bones that we tend to rest (which ends up being the proximal hamstring -- medially the semi-membranosus and laterally the biceps femoris) is not the only reason for this saddle shape. The woman's sit bones are oriented more in the frontal plane (more side to side) than a man's. The male sit bones are set more in the sagittal plane (front to back).
When you factor in the natural translation of the hips and pelvis downward at the bottom of the pedal stroke, you can visualize that the male sit bones can more readily follow this path of movement -- sort of like a knife blade slicing through the dirt. The female sit bones can't move as easily in this path -- imagine running the same knife through the dirt now turned to it's side a few degrees, like a plow. The amount of shear force (or at least the potential for shearing) is much greater.
Essentially, all the angles of the pubic and ischial rami (the structures that form the "loops" on the bottom of the pelvis, and that we sit on) are steeper and sharper and because of this, less contact with saddles is probable. I think this is the reason women often struggle with saddles -- more contact and shear forces -- and not just the fact that they have wider sit bones.
Saddle position
Of course, the right saddle is nothing without it being fit in the right position. Many cyclists are on saddles they are unhappy with, but the reason is that they are not sitting on the part of the saddle that is meant to be sat on. Most are scooted too far forward, even to the point where the sit bones don't rest on the saddle, but rather the saddle is squeezed in between them and the rider is resting more on their soft tissue -- this is a problem, obviously. A huge mistake I see all too often is having the saddle tilted down --- yes, even a little is generally not a good thing.
A bike seat needs to be in the right place fore and aft so that the sit bones can contact the wider, more cushioned portion of the saddle, and then it needs to be level so that the sit bones can rest on it. If you aren't perched on your bike seat, then you aren't effectively stabilized to make full use of your pedal stroke.
_______________
Think about this:
If you have a seat slid all the way back on the rails, so that the seatpost clamp is at the front of the seat, and it is level. What happens when you sit on the saddle? What if the rails are made of Steel? Titanium? What I'm getting at, is that a saddle has a static (or unweighted) position and a dynamic (weighted) position. The dynamic position is the only one that really matters. It has been my experience that especially with titanium railed seats if the seatpost clamp is to the back of the rails the seat will flex downward, if towards the front of the rails the seat will flex backward. Therefore I have allowed some seats to leave my Studio tilted up or down at times to accommodate.
_______________
This leveling of the seat brings me to my last point about a good seat -- for a man or a woman. The seat should have at least some portion of it's surface should be flat and not fully sloping.
This FSA saddle is a good example of when some seat designs can cause trouble for people.
The centerline of the seat is the high point and the cover slopes downward to either side. I am sure there are people who find this saddle comfortable, but I haven't met them yet.
I am intrigued by the new fizik Antares -- the entire saddle looks flat. I will have to try it out and get back to you on that one.
Next up : Some top secret stuff going on in the lab. Well, not really secret, but it should be pretty cool. We are combining the use of the Retul dynamic "mo-cap" with a very sensitive biofeedback system so we can see what exactly some muscles are doing when we pedal, and using all the information (and there is tons!) to try to determine what the leg muscles are doing when....say, a knee tracks laterally more then the other side.
From the preliminary findings, I think I can say that many will be surprised at what we are finding.
--J
Tuesday, March 31, 2009
"Influence of Gender, Power, and Hand Position on Pelvic Motion during Seated Cycling" Sauer et al 2007
Sauer, J.L., J.J. Potter, C.L. Weishaar, H.L. Ploeg, D.G. Thelen. Influence of Gender, Power and Hand Position on Pelvic Motion during Seated Cycling. Med. Sci. Sports Exerc., Vol. 39, No. 12, pp. 2204-2211, 2007.
This first study took trained cyclists and they measured movement through the hips and pelvis at three different wattages (100 W, 150W, and 200 W), on three different saddles (Bontrager X-Lite 2006 mens, fizik Vitesse womens, and Bontrager Race Lite mens), and in two different hand positions (tops and drops).
It did not effectively determine much in the way of gender differences. I think they set out to find out if riding on the drops versus the tops caused more pelvic motion for males or females. Perhaps they were expecting more aberrant pelvic motion among females, I don't know. Overall I think they tried to make their scope too broad -- they were trying to figure out too many things at once. This, I think watered down their results a bit.
They fessed up to their short-comings in their Discussion, which is admirable but still doesn't help to improve the utility of the study. The short-comings they listed had to do with the fact that the women were tested at the same wattage as the men and therefore at a higher percentage of their maximum - so asymmetries would be more pronounced in the women due to a greater relative workload.
The women were also tested on the same handlebar (which had 145 mm of drop to it), and given that the women were smaller, they were forced to relatively lean further forward when they went in the drops.
One other thing I wish they had done, was to include more information and clear photos of the saddles they used -- it can be difficult to find saddles outside of their production year. And saddles can be changed often from year to year, so finding a 2009 fizik Vitesse may not be very instructive.
Things I learned:
The women's ischial tuberosities (sit bones) were (on average) 134 mm apart center to center, while mens were 115 mm. Nearly 2 cm difference in width of the sit bones -- that's significant.
What does this mean for bike fitting? Well, simply women's bike seats should be wider at the back of the saddle so their sit bones can rest on something properly, right?
Well, maybe. Remember, these are averages -- some women have hips shaped like a 13 year old boy, so we need to think individualistically. But also, this study found that the center to center distance between men's and women's hip sockets was NOT significantly different.
This reinforces to me a long-held idea I look for in women's seats (as it applies to a woman who shares these "average" proportions -- remember, we need to take things on a case by case basis): Yes, their seat should be wider toward the back to accommodate the wider ischial tuberosities, but it's my opinion that the saddle needs to narrow very quickly in the middle -- or as I call it, the transition --(essentially the part of the saddle below which the seatpost is clamped to the rails).
To get a visual on the anatomy, check out this link for a view of the pelvis. The bottom picture gives you a sense of where the femurs attach to the hip socket (acetabulum), so when you look at the male and the female structures above it, you can see there is a difference in how the femur relates to the ischial tuberosities.
Consider the fizik Arione saddles below. The little hash marks along each side of the saddle are part of their "WingFlex" technology. This is the transition area that I was referring to. In the case of the Arione, this is very effective for some people -- mainly men over about 165 pounds seem to benefit. Perhaps they are heavy enough to take advantage of the Wings and actually cause them to flex out of the way. I have not found as many women that are comfortable on them.
I believe this is necessary because the gap between where their sit bones contact the seat and the path the femur takes during the pedal stroke is narrower, which can put more shear force on the soft tissue just distal and lateral to the ischial tuberosity.
I feel many women would do better -- and, again, this is a generalization -- on a saddle more like:
Well, not this exact saddle, but it's female equivalent. Some of you may recognize it as a Selle SMP Stratos, and I think the fact that the saddle narrows down quickly (the angle of this picture does not do it justice) keeps the width where it is needed (in the back) and keeps material out of the way of those distal-lateral soft tissues by our sit bones. You can see the actual women's version of this saddle here.
Next post I'll talk about another reason that women's pelvic motions on the saddle differ from men's, since it can't be explained by hip joint or ischial tuberosity widths alone.
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