3D Bikefit owner and head fitter Kevin Bailey works with systems from Retul and Specialized along with proprietary fitting platforms that he designed.

You want your bike to fit. You want to ride fast. If possible, you'd like to look like Mario Cipollini at the apex of his racing career, and like Cippo, have a horse-drawn chariot pull you to the starting line at your next race. Because panache counts.

To reach your best, you pour cash into bikes, gear, apparel, coaches and electronics. You train hard, eat right and go out of your way to recover correctly.

Should a trip to a bike fitter be on your to-do list, too? Can putting a few hours and few hundred bucks into a custom fit really make a big difference? To find out, I pedaled the Giant TCR Advanced SL I'm testing over to 3D Bikefit in San Francisco and spent five hours getting a custom fit.


Retul and Specialized Body Geometry produce the most popular software, motion capture technologies and education systems for fitting. But ultimately the application of these, or any other fit system, relies on the experience and skill of the fitter, thus making fitting both a science and an art.

Located in the heart of San Francisco in the Tendernob area, 3D Bikefit's owner and head fitter Kevin Bailey, a former helicopter pilot, has every conceivable bike fit certification. His studio offers a variety of fitting options using Retul, Specialized Body Geometry and proprietary motion capture, video and software tools. Bailey and his staff are well-regarded and have a loyal following in the Bay Area and beyond.

Broken Human

For the first hour of my fitting session, Bailey ran me through a series of diagnostic questions regarding my body, my cycling experience and discomfort, pain and injuries. After that, he did a hands-on physical evaluation to get a sense of my proportions, strength, mobility and problem areas. He spent more time talking about the specifics of how I feel on and off the bike than I've ever spent discussing my physical condition with any doctor. I move between different shoe, pedal and bike setups more frequently than an average rider, but I've set up the six bikes in my core stable with similar fits.

The 3D Bikefit starts with a look at a rider's body, proportions, injury history and discomfort or pain.

Bailey took particular note of some of the discomfort I've experienced on the bike during the past year. No amount of tinkering with my gear or off-the-bike functional training has alleviated some of the strains I incur regularly including minor tendinitis in my right achilles following 4+ hour road and mountain bike rides along with tightness in most of my right leg focused primarily in my hip flexor, iliotibial band and the attachment points of the muscles in my hamstring.

Bailey's attention to detail and line of questioning demonstrated a deep understanding of the physics, physiology, biomechanics and ergonomics underpinning the seemingly simple but in actuality tremendously complex act of riding a bicycle.

Moving into the actual fitting, the bike gets mounted to a trainer on top of one of Bailey's proprietary, perfectly level fitting platforms.

The Fit

Following the evaluation, Bailey used a proprietary process to create custom-fit footbeds for my Shimano SH-R315 shoes that he claimed would make a huge difference in comfort and power transfer. He then set my bike up on a trainer atop one of the three fitting platforms at 3D that he designed. The platforms can swivel 360 degrees and have been perfectly leveled so that observations, motion and video capture yield perfectly true results.

After mounting the bike, he checked everything again with a level then had me start pedaling. After stopping me several times and having me remove my shoes to dial in my cleat position, he zeroed in on what he felt was my optimal cleat position. While not radically different than the way I have my cleats setup on my other shoes, it felt good to get his evaluation, input and adjustments that I knew I would later apply to the rest of my kicks.

The objective of a bike fit is to maximize a rider's mechanical advantage while balancing that optimal position with comfort. To start off the on-bike component of the fit, Bailey placed tracking dots on my shoulders, hips, knees, ankles and where my feet crossed the pedal axles.

Dots affixed to the rider's shoulders, hips, knees, ankles and feet get used for calculating lever angles following the video analysis.

Bailey used multiple video cameras that would film me from both sides and from the front and back along with Specialized Body Geometry fitting software to get me within spitting distance of an optimal position. Following each tweak, Bailey had me ride on the trainer in the new position while he captured video from multiple angles then used the Body Geometry software to check the angles of alignment between my shoulders, hips, knees and ankles along with the curvature, or lack thereof, in my back.

For the video analysis, video was captured from both sides, as well as from the front of the bike and the back.

After much experimentation, the angles on my right and left sides wouldn't match up. The closer my right side got to optimal, the more out of whack my left side got, and vise versa. Bailey eventually reached the conclusion that the right side of my pelvis seemed to laterally rotate forward resulting in bad angles on my right side when my setup otherwise yielded great body angles everywhere else.

Following the video capture, Body Geometry software helped dial in the fit.

The position I ended up with had me sitting higher and farther forward than I've ever positioned my saddle. Reach and drop remained the same.

All told, Bailey spent about five hours working with me. The fitting completed, Bailey showed me some stretches he suggested I use to try to loosen the tightness in my right leg which he felt might be the source of the lateral rotation in my pelvis. He suggested that I be mindful of how I sat on the bike and to actively practice a more neutral pelvic alignment to have the overall impact that would result in greater symmetry and possibly alleviate my discomfort. I left the shop in a new position that felt different, but fast, and pedaled home.

Immediately following the fitting, Bailey emailed me files with all of the measurements from our session so that I could apply the fit to my other bikes. For riders like me who have many bikes they ride frequently but lack the time and resources to get all of their bikes custom fit, this data provides a big added value.

The Road Test

What works on a static trainer doesn't necessarily work on the road. To me, that's one of the limits of any attempt to optimize bike fit, whether you're doing it yourself or working with a fitter. We've all had the experience of dialing something in at home on the trainer and then having to stop in the first five minutes on the road because it doesn't quite translate to life in motion.

For the next several weeks, I alternated between my 3D Bikefit setup on my primary road bike and the other bikes in my stable. After several hundred miles on the 3D Bikefit setup, I have seen improvements in the discomfort and tightness I experienced in my right leg prior to the fit. Overall, my new position genuinely feels faster and more comfortable than the way I had the bike set up previously. I particularly notice improvements in power output during seated climbing and very aggressive, high-intensity seated efforts elsewhere.


Bailey and 3D Bikefit delivered and for me, their custom fit made enough of a difference that I'd recommend it to you as a very worthy upgrade well worth the cost.

For more information visit www.3dbikefit.com. A variety of fits available starting at $195, fit described $325.

Other Options

If you can't get to the Bay Area, but are interested in getting a 3D fit here is a very partial list of other shops that offer similar services.

Bicycles NYC New York City
Acme Bicycle Co. New York City
Peach Tree Bikes Atlanta
PTS Sports Atlanta
Lucky Brake Bikes Chicago
Velosmith Bicycle Studio Chicago
Boulder Center for Sports Medicine Colorado
Retul Headquarters Colorado
Jack and Adam's Bicycles Texas
Bicycle Sport Shop Texas
Recycle Shop Seattle