Friday 24 May 2013

It's all about the bike fit

Inside a biodynamic bike fitting at Cronometro

July 1, 2012 | 0 comments

I first heard about Cronometro in Madison, Wisconsin, over 10 years ago. I had just purchased my first serious mountain bike online and so had forgone the basic fitting which most shops provide when you buy a bike from them. After many of uncomfortable miles and investigation, I learned from numerous sources that Cronometro was considered one of the best places to get fitted in the nation.

A $200 outlay for a bike fit was a very big deal but I just couldn't get comfortable on my new bike and couldn't figure out why. I ended up talking a friend of mine into making the more than two hour trek down to Madison. We both came away with a positive experience. But while my friend took all the advice and was very happy with his results, I thought I knew better than the professional fitter and only went half way. I kept my new cleat positions, which I've been using ever since, but I disregarded the stem positioning suggestion, which I later came to regret.

Fast forward to about a year ago when my mountain bike phase was eclipsed by triathlons and lots more road riding. After selling my mountain bike and my entry level road bike, which I could not get to fit well, I bought a Cervelo S5 with SRAM Rival which I could ride in a normal road setup and for any triathlon. So last April I found myself back at Cronometro because they are a Cervelo dealer and I was confident I would get a proper fit, provided I followed the staff's advice this time.

A normal bike shop bike fit comes close, but Cronometro is known for its sophisticated biodynamic bike fitting process which I feel is far superior. Colin O'Brien started Cronometro in 1989 and they currently fit over 400 riders a year, so their professional experience is extensive. After taking a history of my years of riding, injuries, current fit issues (such as foot numbness), body measurements and flexibility, I shared my riding goals.

Colin began with a rough saddle height using my existing shoes, pedals and the stock crank arm length which had been determined to be correct for my needs.

Triathlon positioning
The first hurdle would be with the triathlon, position which I had never tried. The age-old fitting adage of "knee over pedal spindle" for road and mountain bike setup goes out the window when seeking an optimum aero position for triathlons. The goal is to get low but still be able to breathe well to put as much power as possible down the road.

The Cervelo's stock saddle wasn't comfortable from the beginning and it was quickly swapped out for a Fisik Arione TRI2 which would allow the saddle to slide all the way forward in the rail clamp and provide the flat saddle design which I prefer. According to Colin, most tri saddles are set up with about a 4-degree down nose angle which balances the rider's weight between the saddle and the elbow pads on the bars. I never knew that people are sensitive to just two-tenths of a degree change in saddle tilt, but this is a crucial area to get right and prevent unwanted numbness.

After swapping out the stock 42-cm wide road bar for a 46 cm one to accommodate my shoulders, we tried a couple different brands of bolt on aero bar extensions until Colin decided I should really be on Vision extensions because of the way my hands wanted to rest naturally and because of their stronger connection to the handlebar since I'm a big guy. This also allowed for elbow extensions to lessen the amount my shoulders hunched and to open my chest area so I could breathe easier.

After messing around with the current stem for a while, Colin got out a huge chunk of aluminum known as a Fit Stem. This device allows him to more easily make rise and reach adjustments. My knees ended up peaking right behind my elbows. I would up with a short 75-cm long, flipped up tall stem. This was a big change from the 100 cm stock. Not having the right length stem is probably why I could never get comfortable on my old road bike.

Throughout the fitting, Computrainer software measured my power wattage through the entire pedal stroke on both crank arms and constantly kept my right and left legs balanced. This was extremely helpful during the handlebar setup. Because it didn't feel like I was on an uncomfortably narrow or low handlebar, the Computrainer was able to let Colin know something was wrong right away and fix it.

Road positioning
While most riders using the same bike for triathlon and road use might swap out the saddle and stem for the most effective position for the training ride ahead, the fitting process for my road position was much less dramatic than the triathlon position. Once the saddle was slid back to allow for the correct knee over spindle adjustment and then nosed up to provide good weight balance between the saddle and my hands on the brake hoods, my power was the same as it was in my aero position. Everything still felt good so no stem or saddle changes were required.

Cronometro keeps a copy of your fit sheet for future reference but also gives you a copy of it with all the measurements needed for recreating your position in case a bolt comes loose, you get a new saddle, crash or get another bike. After all 30-plus points of measurement are recorded for repeatable setup, it was up to Scott Wente to make sure everything worked smoothly and was ready for me to ride away. We added touches, like a tri bar extension water bottle mount which would smooth the airflow between my arms; a double layer of bar tape just on top of the brake hoods for more comfort when riding on rough roads; and my one little splurge, a new yaw-style SRAM RED front derailleur which provided a very noticeable improvement in front shifting and added a built-in chain watcher to keep my new carbon frame free from dropped chain damage.

After all this, does the bike look like the one pictured in the bike magazine ads? No. It looks like it's properly fit for me. And after a couple hundred miles on it I can say that I've never felt more comfortable or been as fast as I am now in my new position.

I found everyone at Cronometro to be patient, friendly and professional in answering all my questions during both the fitting and mechanical setup processes. I went home feeling super excited and very satisfied with all my time and money spent there. I would recommend a thorough bike fitting to anyone wanting to get more out of their biking experience.

Dominic Frandrup lives in Waupaca, Wisconsin, and is the assistant director of the Waupaca Area Public Library. He started mountain biking in college but got bitten by the triathlon bug about 11 years ago after doing the bike leg as part of a relay team and placing first. At age 36, he has yet to own a car and walks to work every day.

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