In the past, a bike-fitter’s work was mostly art. His tools comprised a tape measure, a plumb line and a spanner. Experience and judgement enabled him to position his cyclists at the optimum spot for power, comfort and aerodynamics – hopefully.

In the right hands, these methods still work well. But modern technology now gives us opportunities for a second opinion backed up by science. This doesn’t mean art has been removed from the equation. A good modern bike-fitter will not blindly follow the instructions on the computer screen but use the additional information to achieve the best marriage between bicycle and cyclist.

After several years of racing triathlons on a road bike I finally gave in to the envy induced each time I line my stead up against the array of shiny time trial machines you see at almost every event these days. I’ve also convinced myself that a new bicycle will reduce those incidents of sleek looking cyclists with their even sleeker bicycles flying past me after I’ve worked so hard to beat them on the swim.

Yes, I’m going to buy a time trial bike.

As I’ve never ridden one before I had no idea what size to go for or how to set one up. My research suggested I was too tall for a small sized frame and too short for a medium. Which to go for would therefore depend on other factors such as flexibility, relative arm to body length and comfort. I couldn’t cope with all these variables alone so called in the professional help of Andy Sexton at Bike Science.

Andy uses the Retul system to assist him with bike fitting. This employs a combination of LEDs fitted to key body points and an infrared camera to track the cyclist’s motion. In theory, this is superior to other methods because it is dynamic. It measures angles and position multiple times per second and over many pedal strokes to give a much broader picture than could be achieved by any static or even video capture method.

But first, some basics. Before wiring me to his computer up Andy checked my cleat position to ensure the ball of my foot is over the pedal spindle. He then made me lie on a couch where he twisted my legs in various directions to check my flexibility. Finally he assessed my core strength and balance by doing a few press ups and some single leg squats. I was worried he might recommend a tricycle after I wobbled so much but fortunately he let me continue.

Because I want to buy a new bike, Andy could do all the testing and measurement on his dedicated cycling rig, which is a rather odd looking contraption (see picture). This meant he could quickly switch between small and medium frame sizes and various handle bar and saddle positions to find what worked best. However, if you already have your bike, it’s equally possible to use the system to optimise your position on that.

Looks weird, but does the job

The Retul kit told me a number of useful things including that I sit quite markedly to one side of the bike so that the saddle height indicated by my right leg is higher than for my left. Then, while my right leg moves in a vertical plane, my left knee tends to wobble from side to side. Where these imbalances came from is anyone’s guess. One option might be to pack my left shoe with inserts, but Andy thought that would be just addressing symptoms and not causes so probably best avoided.

Andy works extensively with Planet-X and I will be buying a Planet-X bike. I don’t yet have it, but when it arrives I’m confident it will be the right size and set up correctly. Now all I have to do is get used to it and build my fitness.

A bike fitting costs £175 and takes about 3 hours. Buying the wrong bike, especially an expensive time trial beast, could cost you a lot more than that. Also, Andy can offer a discount to T-Zero members. Please contact us for details.

For more information see www.bike-science.com.

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