For a Better Fit

Real-time trackers attach to contact points across the body.

You may never forget how to ride a bike, but remembering how it should fit is another story. For competitive cyclists, even minute adjustments to the frame can have a major impact on comfort and performance. Despite this, bike fitting has long been a black art with each technician employing her own method and metrics (plumb bob, video, rulers, etc.). Most methods have been inaccurate, tough to reproduce and based on the static position of the rider (not pedaling). Meanwhile, opposing views on the “right” fit have been difficult to reconcile without a standardized measurement method. Now Retul has introduced a motion-tracking system that may put those issues to rest.


Markers on the thigh and knee transmit real-time data to professional fitters.

Eight LED sensors and custom software provides real time 3-D dynamic analysis of the bike-rider orientation. Retul introduced the $10 thousand system late last year and already 40 high-end bike shops around the country have acquired them—a boon for wannabe-Lances across the country. The Slipstream cycling and the US Olympic Triathlon team had fittings done at Retul’s homebase in Colorado ($250 per bike, bike not included).

“Bike fitting can make a huge difference in your efficiency,” says Franko Vatterott, co-founder of Retul. “Before you go and drop money on all the carbon fiber bling, getting your bike to fit correctly could make an even bigger difference.”

Fitting is focused on contact points between the bike and the body: seat, pedals and handle bars. Once a cyclist has chosen the right size bike, a handful of adjustments can be made by a qualified fitter specific to each rider. The complete personalized consultation can take up to two hours. A leg length discrepancy might receive a simple shim to ensure the knees are pumping straight up and down. A triathlete might sacrifice a bit of performance to ensure he’s comfortable enough to complete his run. A cyclist traditionally ignores comfort for drag reduction, though in the off-season things might be dialed back to reduce injury risk.

“We’re not telling them what to do, because we don’t know yet,” said Vatterott. “These [fitters] have been craving this. They fit thousands of riders and they all think they know the right way. Now every fitter in our network knows what others are doing.”

With a single system, a nationwide database, and defined marker locations (three on the foot, knee, hip, shoulder, elbow, wrist) mechanics and cyclists will finally be speaking the same language. It won’t provide quick answers, but at least the arguments can begin than can lead to better fitting and better bikes.