Lasers show up on the rider as he sits on a bike

Sports technology: Bike fitting

This month’s sports technology feature looks at the technique of bespoke bike ‘fitting’, where a bike can be exactly adjusted for the rider to achieve maximum comfort, flexibility and performance.

Last summer, like many men of a certain age, I watched the Tour de France sweep along the roads of my home county of Yorkshire and immediately went out and bought a road bike. For a mountain biker with 30 years of experience, this was close to heresy, but even so, within a few weeks I’d become slightly obsessed with my new machine - so much so that four months later I bought a second road bike on a principle well-established amongst cyclists: the optimum number of bikes to own is n+1 where n= the number of bikes already owned.The list price of the second bike was over four times that of the first (which in itself wasn’t especially cheap), so having invested a not inconsiderable sum in a vehicle that doesn’t even have an engine, it seemed only sensible to splash out a further £90 on a ‘bike fit’ at York Cycleworks to ensure I rode my expensive new carbon-fibre steed in the optimum position for efficiency and comfort.

Being ‘fitted’ for your bike is pretty much de rigeur these days for any cycling enthusiast, and absolutely essential as far as high end riders and pros are concerned. Sure, anyone who has owned a bike for more than just popping down to the shops may have adjusted the saddle and handlebar heights to get a more comfortable ride, but a proper bike fit is much more than this.

Comfortable fit

My ‘fitting’, for instance, was done using the Trek Precision Fit system, which analyses the relationship between the rider and the bike’s components to ensure everything operates in harmony, with great importance placed on your range of motion, flexibility and symmetry both on and off the bike. The eventual fit measurements are recorded for reference, so if you change your bike, the updated model can have its geometry adjusted to suit you.

The whole process takes about three hours and involves: an interview to find what your goals are from your bike riding (from Sunday afternoon jaunts to full-?on racing); a physical assessment for the above mentioned range of motion and flexibility; an analysis of your cycle shoe set-up to ensure your cleats (which clip into the pedals) are at the optimum setting, and an evaluation of your current position on the bike.

The system has been developed by Wisconsin-based Trek Bicycles over the last couple of years in partnership with expert bike fitters in the USA and UK (in the latter case, the well-?established Cyclefit UK in London’s Covent Garden), and uses a bike-fit machine.

This is essentially a rudimentary bicycle frame, saddle and handlebars mounted on a platform on which the geometry can be adjusted for an exact match to your own bike which you bring along with you (in my case, a Cannondale SuperSix Evo 2). Trek’s system can be adapted to suit any make or model, but if you’re also in the market for a new bike, the software will recommend the best bicycle for you after the fitting process is completed, albeit within the Trek range.

The actual bike fit is an appraisal of your cycling physiology, technique and alignment as measured on the machine, with the aim of enhancing your riding experience by improving your level of comfort on the bike, safeguarding against injuries resulting from a sub-optimal riding position and increasing stability and efficiency while reducing fatigue.

I ask Matt Gehring, Trek’s product and programme manager for Precision Fit, what kind of rider can benefit from the system. He replies: “Pretty much anyone really. Most people we see are regular cyclists who are uncomfortable on their bike for one reason or another, but we also get riders who are looking to improve their competitive performance. Our view is that it doesn’t really matter whether you’re riding recreationally for four hours a week or training for 14 hours a week; there’s no reason why you should be uncomfortable.”

I’m definitely a ‘recreational rider’ category and I used the Precision Fit programme to help ease chronic lower back pains I experience when riding. At the other end of the scale, Gehring told me how four-times world time-trial champion Fabian Cancellara of Switzerland has used the system to offset a small difference in the pedalling strokes between his left and right foot, whilst Dutch pro Bauke Mollema used Precision Fit to improve his time trialling after last year’s Tour de France.
In brief, the process involves adjusting your position on the bike, assessing whether you have the optimum handlebar dimensions, stem size, saddle height and fore and aft position, as well as analysing riding position and style in real time with motion capture software.

This is essentially a variation on a technique used by other bike fit systems such as Retül, which is so effective it was recently purchased by cycle giants Specialised. The Retül system uses infrared LEDs stuck to various parts of the rider’s body. These are filmed and fed into software that has a database of normative ranges of pedalling action, which informs the fitter when the client’s position is within the range that suits them for the type of riding that they wish to do.

Trek’s system

This kind of motion capture software is an integral part of the fitting process. The Trek system, for instance, captures the rider’s cycling action at 60 frames per second, allowing the fitter and rider to focus on where and how improvements in technique and riding comfort can be achieved.

“We can actually show people what is happening as they pedal”, Gehring says, which means there’s no danger of a client believing the fitter is fabricating things to justify the cost of the fitting. I can verify this: during my bike fit I was told I was applying more pressure while pedalling with my right leg than my left, which was causing a minor lean to one side. This could be seen on both the motion capture footage and graphs of power level outputs for each leg. It was relatively easily corrected through a combination of new footbeds in my cycling shoes and the installation of slightly narrower handlebars.

Gehring points out that while you are cycling “much changes in terms of your body’s position on the bike which simply cannot be seen by the human eye, seeing things at the equivalent of 16 frames per second as opposed to the 60fps of motion capture”.

However, the technology is only as good as the fitter using it. All Trek bike fitters must attend a three-day course involving the study of anatomy in relation to cycling, applying that to the fitting process and hands-on work with instructors.

The fitters will still require as much practice and experience as possible to be really effective, says Gehring, and the company has also introduced a Level 2 course for more advanced fitting. This focuses on saddle pressure monitoring and reveals ‘hot spots’ on the saddle which may be causing discomfort. It also looks at whether a rider’s pelvis twists as they pedal, and their general movement on the saddle.

The course was developed with the help of the Trek mountain bike team. All the members of the team tested the firm’s new Montrose saddle, developed with pressure monitoring. By the end of the trial period, the entire team had switched to the new saddle.

Despite all the evidence that being professionally fitted for your bike does result in a more comfortable and efficient ride, many cyclists are content to tinker around at home trying to get their bike to work for them.

A few may achieve it, or your bike may work well for you with just the basic adjustments of saddle and handlebar position. If not, it seems somewhat contrary to spend a four-figure sum on a bike and then not bother with a bespoke fit.

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