New location

Come on over to my new site:

Going to be posting regularly there.

Thursday, August 30, 2012

Lenz Mammoth -- my "PT Barnum" bike

 So, I know the red silicone grips are a bit much, but I couldn't resist.  Hence the "PT Barnum" moniker -- it has a circus feel to it.

Usual suspects on the build:  White Brothers Loop 140 fork, Fox CTD rear shock, SRAM X.9 (with an X.0 bit here and there, Answer Pro Taper AM carbon handlebar.

This time around I just used some Sun Ringle Charger wheels for display -- not the lightest wheelset, but they licensed the Stan's rim profile so they tubeless great.  Couldn't resist the Schwalbe shoes on the bike -- I'm particularly impressed with the "Hans Dampf" on the front.  It's a good, stout tire but it rolls well and this one came in at 870 grams -- which feels downright XC-like when you've been riding an 1100 gram Descent.


Monday, August 27, 2012

End of Summer Discounts: Wilier-Triestina, BMC, Lenz Sport

Moving last year's bikes; Retul bike fitting still included with every bike
I have a couple of DEMO BIKES left that will be going at even steeper discounts (even a 29er or two -- actually 6).

Call or email with any questions :

BMC Road Racer, bare gloss carbon finish; I have two of these left, both "54"s (55cm effective top tube [TT])

BMC Speedfox 29, X.0, Easton carbon, Fox fork -- sizes S and M available

BMC Road Racer, full Ultegra, size 57 (normally $3600, now $3059)

BMC Street Racer - Shimano 105 group, sizes 48 and 51 available for you vertically challenged folks.  (not $1799, that's full retail)

Our most popular bike this year, the Wilier-Triestina Gran Toursimo.  We've cycled thru a lot of these and I have 2 left, a 55 (nominally a Large) and a 52 (Small)

One white Wilier Gran Tourismo left, a 57/58 (X-Large)

BMC RaceMachine - size "53" (has a 55 cm effective TT) - this was a demo bike and will be discounted further than some of the others

Lenz Sport Leviathan; 4.0; Sun Ringle (Stan's) wheels, SRAM X.9 drivetrain, Hayes Stroker disc brakes; full retail $5200, now $4200

BMC Team Elite 29; probably one of the best entry level 29er deals out there; solid Shimano SLX build, Rock Shox Recon fork; Hate going over the handlebars? this race ready bike has better geometry than most 29ers out there -- look it up; no 29er should have a head angle steeper than 70 degrees (IMHO)

I have 3 of these left, two Mediums and a Small

Run blog today

Even if you're a two-wheeled athlete, I posted on my running blog for anyone interested in speed work -- look for more posts on this as I try to get back on the track and make my slow legs slightly less slow.

Sunday, August 19, 2012

What should my next bike buying experience look like?

It wasn't too long ago that the normal bike purchase was a pretty quick, very un-scientific affair.  Unfortunately, that is still the case for a large majority of cyclists.

Luckily, in the last 10 or 15 years the bike fitting movement has led to more engagement during a trip to your local bike shop (LBS), as well as happier riders.

What is bike fitting?  Essentially it's making sure that a bike frame and all its component provide an efficient and comfortable bike ride for the cyclist.

Who needs one?  Well, everyone....especially those that ride more than once or twice a week.  Not everyone needs to spend hours getting fit, but it wouldn't hurt.  A poorly fit bike creates pain, injury, and can even lead to the urge to toss your bike off a bridge overpass.

At my Studio, every bike purchase comes with a free bike fit and follow-ups for the first year, and it's common that we spend 90-120 minutes using infrared motion capture technology to dial in their position.  No, many cyclists could get by with much shorter appointments and come out not too much worse for wear, but if you think a poorly fit bike isn't very common, I would direct you to the 200 or so non-purchase bike fits I do every year.

So what should a bare-bones fitting consist of?

1.  Interview - Sit down (yes, sit down....this conversation shouldn't occur while the employee is wrenching on a bike, or manning the register) and spend a few minutes explaining how you're going to ride the bike --  where?  how often?  type of terrain?  goals for this bike?  etc.

2.  Physical Assessment - The employee doesn't need to have a degree in exercise physiology or practice as a PT (although, again, it wouldn't hurt) but they should be able to run you through a few simple physical tests for flexibility and strength to get even a vague idea of your abilities.

3.  Bike Assessment - At this stage you should be on the bike, preferably in riding clothes.  Not spinning around the parking, but rather with the bike set up on an indoor trainer so that your posture can be viewed for more than a few seconds at a time.  Beware of anyone declaring the fit "good" after just a minute of watching you.  Even just getting the correct saddle height usually takes a few adjustments to see how you respond to higher or lower positions, and then handlebar height and reach is likely to be changed at least once before moving on. 
 How do you determine if it's "good"?  If you have a fitter who you are certain is very skilled at bike fitting (not just bike fixing or selling) you can rely on their expertise some, but they should always be constantly assimilating the feedback from you based on nothing more than "how it feels."  If you suspect your fitter is just so-so, then you should lobby for spending as much time on the bike as you can before plunking down the cash.  If you're on the indoor trainer, ask lots of questions, delay a bit or just ask for more time - tell them to go away for 10 minutes while you ride.  Don't be afraid to ask even for an extended test ride; some shops let you take the bike overnight and get in an actual ride.

4.  Follow-up - Ask if follow up fit sessions, even just quick tweaks, will be included (for even a few weeks) since you are likely to find new issues when you spend a full hour on the bike on varying terrain on the road or trail.

All in all this could take anywhere from 30 minutes to two hours, but think of it as an insurance policy.  The better your bike fits, the more likely you are to ride your bike....which is the point after all.

--John Weirath, PT is a (very slow) runner, cyclist, and triathlete that builds and fits bikes to clients one at a time at The Bicycle Studio right here in GJ. // // 970.255.0055

Friday, August 10, 2012

Lenz Mammoth Tire Clearance

An old Maxxis Ardent 2.4 (on a Stan's Flow rim) in the new Lenz Mammoth
 Nice to know that the Lenz Mammoth will take nearly any tire you can throw at it.....

Seat stay

Chainstay -- I shot this at an angle so the non-drive side looks really close but it has the same gap as this side

Monday, August 6, 2012

Bike Fit 102: Elvis the Pelvis

The pelvis is not typically addressed directly by the vast majority of bike fitters, and that's not much of a surprise.  The pelvis and all its parts (yes, each side of the pelvis is made up of at least three distinct bones, and that's not including the sacrum or tailbone) is a difficult-to-visualize structure that nevertheless provides our main base of support on the bike.

Some important features of the pelvis are the acetabulae or hip sockets and the location of these is usually poorly understood.  When you mention "hip" to most people they typically point to the bone on the outside of the thigh/buttock area, but this is actually the greater trochanter -- merely an exterior bony landmark.  The actual hip joint exist a few inches further in toward the center line of the body from this landmark (and above it as well, so when palpating the trochanter of the hip think "in and up" and you'll have an idea where  the hip joint actually lies).

The perineum is also extremely important in bike fitting because this is usually the sensitive tissue that gets very irritated with a poorly fit bike.  Whatever you want to call it -- taint, under-carriage, naughty bits -- it's important to understand how and why it comes into contact with the saddle in different fit postures.  In my experience, the strength of a rider's pelvic floor muscles (muscles that form a sling or hammock on the underside of the pelvis) combined with their pelvic posture and mobility will go a long way toward determining what positions on the bike are feasible and which are not.

The sacrum is the tail (bone) end of the spine and it rests pinched between the ilium and so the joint on each side of the tailbone where they articulate is called the sacroiliac (SI) joint.  The SI joint is a common source of back pain, and as I've mentioned in previous posts (here and here) the small amount of movement (or lack there of) at the SI joint can cause some deviations in the pedal stroke from one side to the other.

Another important note is that the hamstrings attach to the ischial tuberosities (the part of the pelvis you actually sit on -- which is why they're also called sit bones),so the relative strength and mobility of the hammies can affect how the pelvis moves as well.

All of the features above (and many more) all contribute to what I call the "effective pelvic position" (EPP).  The EPP is the tilt that an individual's pelvis "wants" to perch on the saddle.  It can sit at a different angle than this but then aberrant forces will be put through the pelvis creating a disconnect between the upper chain (the spine) and the lower chain (the hip joint and femur).

A couple very common examples:

I may see an older male rider that has tight hamstrings and decreasing lumbar and SI flexibility and in order to effectively fit them I'll have to get their pelvis tilted forward only about 10-15 degrees from vertical -- fairly upright.

Conversely, a very fit young rider, even one with  moderately restricted hamstrings but excellent lumbar mobility (and very strong pelvic floor and transverse abdominal muscles) may be most efficient with an EPP closer to 25-30 degrees from vertical.

The ultimate goal, as with all of bike fitting is to get the rider balanced on the bike as best as possible -- and this is usually evidenced by a smooth pedal stroke, a decrease in lateral hip and knee deviations, and better engagement of the abdominal muscles, along with more comfort, power, and fewer aches and pains.

On rare occasions we will see someone with a fully vertical EPP or even tilted posteriorly (backwards).

Why is any of this important?

In my experience, a rider's pelvic posture is one of the biggest determinants of their handlebar position.  This is an enormous generalization, but the more anteriorly (forward) tilted pelvic postures match with longer and lower bar positions.

When the pelvis is tilted more forward then the lumbar spine is directed towards the handlebars more than with a vertical EPP which angles the spine more toward the sky.  When the spine is directed more vertically, then in order to reach a longer and/or lower handlebar position the rest of the spine needs to be exceptionally flexible to flex forward and complete this posture.  If it's not, then the motion will inevitably come from the shoulders and shoulder blades in the all too familiar super-stretched position:

Obviously an exaggeration but it goes to my point - clearly the pelvis can't roll forward any more (even though it's only tilted about 35 degrees or so) and so the extra distance is compensated by an enormous extension through the shoulders.

There are certainly times when a fit, strong rider will have a fairly vertical EPP but still will tolerate an aggressive long and low bar position.  As I mentioned before, they'd need to have a lot of abdominal stability as well as flexibility in their spine, but it certainly is possible and sustainable for a few riders.

Once we understand the EPP idea then we can address probably the most under-rated aspect of bike fit -- saddle tilt.  Saddle tilt plays, I think, the biggest roll in assuring the rider is balanced on the bike.  If we start with an understanding of the right saddle height (for more read here), we get the tilt and the fore-aft of the saddle right then we can be half way to a stellar bike fit.

My simplest explanation of how to adjust this tilt (and fore-aft) -- basically you need to know where and how the pelvis wants or needs to rest and then move the saddle under it to that position.  I know it sounds a little abstract, but once you have a good understanding of the pelvis you can make this happen.

Happy Pedaling.