Chris Writes.

It was entirely due to good luck that I happened to be able to be able to get my bike fit at the Boulder Center for Sports Medicine. I was in Boulder on other business, and was able to arrange a 2.5 hr fit session with bike fit rockstar Sean Madsen, a guy who undisputedly now knows far more about the workings of cyclist knees, feet, hips, shoulders, backs, and wrists than nearly anybody. I owe him a massive thanks for his time and his help.

Sean Madsen from BCSM looks on as I pedal while covered in tracking dots

This is the part where I say “Well ya know, I did my share of bike fitting way back when I worked in a shop…”  I’ve been riding bikes for the better part of 18 years now, and save for the occasional non-bike vacation or that bit where I was in school, there hasn’t been much “off the bike” time.  And while it’s true, I’ve never actually won a race (though I once got 2^nd), I think I’ve got a decent understanding of bike fit.  Or at least, I thought so.

Side view of the tracking dots - note the red cameras!

In recent years, I’ve learned even more as the science and physiology of biomechanics has blossomed bike fit from a pure art form into a unique science.  It’s a science where the algorithms are well established, yet remain flexible enough to accommodate each individual rider.  Yet despite my familiarity with the concept of fit, and despite my own experience, it was the process of actually going through it that really made me realize how far this has come.  From the physical assessment of flexibility and asymmetry, to being filmed with six cameras and those 3D tracking dots they use to create animated Golem characters, I was in awe at the undeniable precision.  I’ve seen this stuff on paper, plenty of times.  But this time it was me, and those circles being drawn on the screen were the ellipses of my knees, wavering and weaving left to right as I pedaled up and down.  These spiro-graph doodles that the heartless and whirring HAL-9000 machine was displaying were uncaring, ruthless, and perfect.  And they showed me, by exactly how much, that I was not.

I was riding my bike on a trainer under the 6 laser-beam equipped cameras in the lab.  The cameras and their computer tracked the 16 reflectors on my knees, feet, and hips to within a few millimeters in 3 dimensions.  I was pedaling at a fixed 290 watts.  After a healthy sample of about 4800 readings (16 sensors, tracked for about 5 seconds at 60 frames per second), Sean and I reviewed my results: my knees were too bent at the bottom of the pedal stroke, my back wasn’t curving right, and I was pedaling with my heels lifted all the time.  My knees weren’t optimally aligned over the pedals, and because I have a slightly longer left femur (who knew?), I was pedaling slightly crooked, so that my knees weren’t perfectly mirror images of each other.  Basically, I was pretty good from far, but up close, far from good.

We ended up dropping my saddle and my bars (yes, that’s right, my legs were too bent at the bottom of the stroke, but we dropped my saddle).  We adjusted my cleats, and I got back on the bike.  Cameras aglow in their sinister laserbeam red, I spun the bike back up to speed and waited for Sean to bring the wattage back up to 290.  It never happened.  Or rather, it did, but I never felt it.  These few small tweaks let me pedal at the same power, but at a far lower perceived exertion.  It was not subtle.  My center of gravity dropped by more than a centimeter, my bars dropped nearly 2cm, and my cleats now adjusted to accommodate for leg length discrepancies, I was now oddly unchanged, yet stronger.  I didn’t feel like my bike fit differently.  Sean simply unlocked some of my muscles.

6 of these, staring at me.

Apparently there were two big things at work here: one is that I am now able to utilize more of my gluteus muscles, which apparently are the strongest muscles the body has.  Second, because I was always pedaling with my toes pointed down, my calves were never getting a chance to relax, eternally flexed out yet not firing and providing power.  My seat was too high, so I was pointing my toes to reach the pedals. By pointing my toes, I wasn’t getting proper leg extension.  Dropping my saddle let me drop my heels, get better extension, use more muscles, and abuse my calves less.

Had it been up to me, I would have started by raising my saddle.  This would have been exactly wrong.

So what’d we learn?  A few things: first, the science of bike fit has more to say about the interactions of the entire body with the entire bike than it has to say about one specific aspect.  It’s chaos theory and butterflies in the Amazon, but it’s an ecosystem where, at least in a lab, you can clearly see and measure the effects of a change in position on not just that element, but the rest of the rider as well.  And the art form has moved from the knowing glances of a wizened Italian sitting in the corner with an espresso, to a scientist in Colorado who can measure everything, but still has the insight to know what to change to bring the entire system into alignment.

Second, I suspect that this might be uncomfortable for people who’ve been doing this for a long time.  The past generation’s gurus of bike fit, while probably well worthy of the acclaim they have earned themselves, are now at risk of being outmoded by a system that is more ruthlessly reliable, more quickly taught, and more accommodating to specific & individual rider needs (especially when, say, your left leg is 2 or 3 mm longer than your right).  It doesn’t make the Gurus any less talented.  It simply makes them less unique.

Third, this sort of scientific approach feels nothing like the inside of a bike shop.  I walked into the Boulder Center having no idea what to expect, and was rather surprised to find that it felt as clinical as it did.  Apart from a few exceptions I’ve seen (like the fit room at nearby University Bikes), the confidence and assurance of this laboratory was decidedly unlike the archetype of your neighbourhood bike shop.  But the fact that bike shops can learn how to do this, and that this fit technology has become available all over the planet within the past 3 years – well, it’s all rather stunning, and gives me hope about what the future of a great bike shop environment will be.  In some cases, it’s already there.  And that’s just cool.

Three tracking dots per shoe