Bike Fit Screen Shot

I was at Element Multisport the other day when Chris and Dave were fitting a young lady on her road bike. It's quite a system that they have at Element for the bike fit. This lady had opted for the Retul fit which takes advantage of some video game like "motion sensors" that utilize infra-red LED's to capture you motion at specific locations on the skeleton. The main points the Retul system is attached to is the foot, ankle, knee, hip, shoulder, elbow and wrist.

The Retul system pick up the LED signals every 2.1 milliseconds (476 times per second) and is transmitted to the sensor and computer in real-time, relaying actual angles in a 3D fashion.

The lady that I was watching get fit has some fairly serious biomechanical issues with the fit she had recently recieved when she had purchased her Canondale down the street.

To the left is the screen shot that was pulled off the computer after the fit. If you look closely at the circled area, that is the path that the knee sensor was taking before and after her fit.

On the left, you can see a figure eight pattern. Her knee was coming up and in on the up-stroke, back to the outside, then back relativley straight and then started the loop back to the outside.

If you knee is wiggling in a figure-8 pattern like this, you are loosing a lot of power while increasing your risk for a knee injury.

After her fit, you can see the path that her knee was taking (right side) with the elimination of the figure-8 pattern, which has increased her power and efficiency! The fix was as simple as placing a 1.5mm Varus shim between (thicker on the inside, thinner on the outside).

If you are going to spend more than $200 on a bike fit, it would make sense to me to use the Retul system in conjunction with a certifified bike fitter.