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Bay Area fitter utilizes exclusive 3D technology for in-depth bike fits

  • By Lennard Zinn
  • Published Feb. 20, 2013
  • Updated Feb. 20, 2013 at 10:02 PM EDT

BOULDER, Colorado (VN) — Kevin Bailey and his 3D Bike Fit team have incorporated a huge amount of technology, combined with Bailey’s encyclopedic understanding of anatomy and pedaling efficiency, to produce state-of-the art fitting in downtown San Francisco.

Bailey is a certified Specialized BG bike fitter and uses Retül video equipment along with Specialized Motion Capture technology and training. He uses these two systems simultaneously, along with two ingenious, impeccably engineered bike-fitting platforms he has built himself, which disengage with a latch and flip around 180 degrees.

Thanks to the rotating fit platform, the fixed video cameras that continuously record the positions of the Retül sensors adhered to each leg and arm joint of the rider capture the rider from not only one side, but from both sides, and from the front and back. Other fitters using video-capture dynamic fitting systems generally only record video of the rider from one side and from the front, but by flipping the rider and bike around exactly 180 degrees, 3D and its software create computer stick images of all of the rider’s levers moving in space from all four sides — twice as many as other video fit systems. Indeed, Bailey claims that 3D Bike Fit provides more data sets than any other fit system in the world, and the report 3D provides to the rider has both a Specialized BG bike fit report as well as a Retül bike fit report included.

3D Bike Fit has two huge video screens in front of one end of the fit platform. One of them is playing live video from the motion-capture camera taken from one side, while the other is playing taped footage. This allows the rider to view, for instance, his pedaling from both sides simultaneously, or video taken in his old position alongside live video in the new position.

Bailey was formerly a professional helicopter pilot, and that career has played an important role in his bike fitting and the equipment in his fit studio. All of those years flying helicopters kept him crammed into little cockpits for long hours and at extremely odd times of day. (Did you know that helicopters fly all night over farm fields when the temperature is below freezing to push the warm air coming up from burning smudge pots down onto the crops?) Flying in these conditions was hard on Bailey’s body and, he says, “Everything hurt on the bike; I had every fit problem that you see!” His motivation to learn about bike fit stemmed from this. And his experience building special tools and fixtures for lifting unique items with a helicopter came in handy in building his fitting fixtures.

Because of all of his body pains, Bailey also learned a number of stretches to improve comfort on the bike, several of which he taught to me when I was visiting for a bike fit. Two of them, for stretching the ilio-tibial (IT) band and for stretching the hamstrings, are the best ones I’ve ever tried, and I continue to do them daily, two months later.

A fitting

Bailey started my fit by putting me in bike shorts with holes at each hip bone so that he could stick the Retül sensors directly to my skin and not have them fall off or move on the surface of the fabric of my own shorts. I pedaled my travel bike on a trainer on the 3D fitting platform. Video cameras captured my movements from both sides as Bailey flipped the platform around from one position to the other, 180 degrees away.

I’ve undergone a lot of bike fits, and I had some pretty fixed ideas about it as well as fixed ideas about what saddles I could use comfortably. Bailey changed both my fit on the bike and my saddle, things (especially the latter) that I thought I would neither allow nor be able to tolerate. After a couple of months, I’m coming to like both.

Bailey changed my saddle to a radically different model and, relative to my old saddle position, set the new one lower by one centimeter and pushed it forward by 1.6cm. He changed my Speedplay pedal spindles to spindles that are 1/8 inch longer, reduced my reach to the bar by 3.8cm, reduced my drop to the bar by 2.8cm, and narrowed my handlebar by 2cm, from 46cm to 44cm center-to-center. He changed my saddle from a Selle San Marco Rever to an SMP Dynamic with a dramatic “eagle’s beak” shape and wide, full-length split. Bailey also diagnosed a leg length discrepancy, something that came as a surprise to me, as I’ve had X-ray diagnosis at Boulder Center for Sports Medicine of perfectly even leg length, and he put a valgus shim under the orthotic in my left shoe. I removed the shim as soon as I got home, but I left the other changes to my bike intact. I did this fit in San Francisco with Bailey in November, at the height of cyclocross season, and now it’s cross-country ski racing season, so I have not ridden my travel bike a lot since, though I’ve been comfortable whenever I have done so.

Even though I am very interested in SMP saddles and know a number of riders who swear by them, I never envisioned myself on one. Since childhood, I have a condition called varicocele, and anyone who knows about this can understand why I have always sat off to the left of the saddle slightly and always preferred saddles with a narrow nose, no split or hole in the center, and wide and flat rear section. I knew I sat off to the left and always have; I just saw no solution to it. With the SMP saddle, I have surprised myself in managing to keep my trunk, and hence my pelvis, centered without much pain. This is an ongoing process, and I do believe that my pedaling has improved as a result. Because of the shifting on the saddle required, I can’t see any way that I could use an SMP saddle in cyclocross; Bailey prescribed a Specialized saddle for that, but I have not made that switch.

3D’s unique technology, combined with Kevin Bailey’s decade-plus of fitting study and experience can help some riders become more comfortable and more efficient than ever on their bikes. And being able to see themselves ride in their new and old positions, and from both sides, on huge video screens allows those riders to understand their fit, thus reducing the likelihood of them second-guessing the fit and changing things around themselves. It also allows them to incorporate much of Bailey’s wisdom, which often comes in the form of tips or images, like, “Just use the hamstrings to unweight the pedals and never pull back on the stroke or simulate scraping mud off the shoe,” or, “You get leverage from the hips and glutes; energize your main fulcrum,” or, “We’re using tangential energy,” or, “Free the levers to do their work,” or, “When pedaling, always imagine you have an egg under the forefoot, and, if you pedaled with too much force downward from your lower quad, you would break the imaginary egg; this helps encourage the back/glute pedaling style for more sustained power, which is easier on the knees.”

Editor’s note: This story initially declared that 3D Fit had made alterations to Specialized’s BG Fit software. Kevin Bailey has since told us that this is not true.

FILED UNDER: Bikes and Tech / Injury Prevention and Treatment / Training Center TAGS: / /

Lennard Zinn

Lennard Zinn

Our longtime technical writer joined VeloNews in 1987. He is also a framebuilder, a former U.S. National Team rider, and author of many bicycle books, including Zinn and the Art of Mountain Bike Maintenance and Zinn and the Art of Road Bike Maintenance, as well as Zinn and the Art of Triathlon Bikes and Zinn's Cycling Primer: Maintenance Tips and Skill Building for Cyclists. He holds a Bachelor’s degree in physics from Colorado College. Readers can send brief technical questions to Ask LZ.

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