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Bike fitting an art or a science? by Luis
Posted 01:01 PM, February 02 2006
Mark Allen fitting Luis at the clinic
Mark Allen fitting Luis at the clinicOver the past two months I have reported to you on the process of purchasing a bike, changing components to turn it into a triathlon bike and finally on getting the bike fitted to me. I mentioned that once you paid 1500 to 2000 dollars a more expensive bike will not get you to go that much faster. You are better off paying for a professional bike fit so that you can become one with the bike. Well, bike fitting also has its own limits. Once the fit gets to be close to a good fit, it gets real hard to tell exactly which position is best. Bike fitting can use science and technology to help you but there is a lot of art too. No wonder Mark Allen tinkered with his position almost every year and Torjborn Sindballe fresh off his record setting bike ride in Kona last October is still tweaking his position. It always helps to add some finishing touches for that perfect masterpiece.

Before I get into the details of the fit clinic I attended let me discuss your traditional bike fit. This is a bike fit close to the ones available in most areas. You make an appointment and you bring your bike to the local bike fitting expert. The fitter watches you on the bike and takes a look at your position. Experienced fitters may take measurements of your angles. They may look at your foot/knee alignment and potentially they may check your flexibility. From this they may change a few things on your bike. This can be your seat position up/down or forward/backward. In some cases they may change the position of the elbow pads on your aero handlebars. Perhaps they may change the cleat position for your shoes. That is all great of course if it helps you to be more comfortable and ride faster. However what happens if the changes you make are not sufficient? What if no matter how much you move things the position is not optimal? Now you have a dilemma. A good bike fitter may just tell you that you need to buy a new stem, or a new seat post or potentially a new bike. This of course is not great news to many people that are on a budget. Potentially the triathlete may think this is a rip off and if the bike fitter works for the bike shop it may be perceived as a way to make more money. Usually bike fitters are not shy when the position is absolutely horrible. But as the position gets closer to a good one there may be a tendency to not ask you to spend money for a small change.

There is also another dilemma faced by bike fitters that may prevent them from making too many changes. We all know that once you change you position you need to give your body time to get used to the new position. The last thing a bike fitter wants to hear from a client is that once they rode the new position some pain developed. Not only is this not good for the actual client but it real bad for the bike fitter and his/her business. News spread real fast. Even if the client did not listen to instructions and decided to go do some speed work on the new position, it is just not good for business. As a result many fitters get real shy at changing too many things once the position is close. Plus here in America there can be lawyers involved.

Bike fitting is not a science; there is some room for variability. Besides there may not be such a thing as a perfect bike fit. Plus the reality of the bike fitting business with outside pressures such as liability make it so that even after visiting a bike fitter you may not finish with that optimal position. Ultimately the athlete needs to take responsibility for using the bike fitter’s advice, making additional changes or perhaps go back to the old position. The ultimate test is how you feel once you get on the road and ride the bike.

Mark Allen and I recently visited the bike fitting clinic put on by Dan Empfield in California. Dan is the former owner of Quintana Roo bikes and wetsuits. Dan basically pioneered the construction of triathlon bikes which allowed triathletes to have forward positions by having steep seat tube angles. Dan’s methods of fitting a triathlete to his bike is slightly different that the one I described above. First Dan has what is called a 'fit bike'. This is a special stationary bike that allows for changes of many the lengths of all the important elements on a bike. You can rapidly change the seat height, the seat angle by moving the seat forward or backwards and the position of the handle bars up, down, forwards and backwards. With all these changes you can have the dimensions of any bike and have the rider try any of them for comfort. Dan’s axiom is the body knows what position is optimal. With this in mind he explains a protocol to follow with each athlete where the client tries many positions until one is found that the client prefers. The bike fitter will change all the dimensions and attempt to get the client to tell you which position feels good or which feels bad. Once you follow the protocol Dan can almost assure you that if you measure all the clients angles they will fall closely to the same angles used by many top athletes around the world. We tried the method during the camp and Mark Allen fitted me using the protocol. Sure enough as predicted the position I liked was similar to what the top professional use. The position was definitely more forward than what I had come up with at my 3D bike fit. So I decided to give the position a try. In many cases changing someones bike to match the one discovered via Dan's methods can be challenging if not impossible. Fortunately all that was required in my case was a different seat post that allowed even more forward positioning than I had. I did not need a new bike. The difference here from a traditional bike fit is that the position was chosen by the client himself. This goes a long way to customer satisfaction. When the client says 'it feels great' it is always a good thing and he may want to get a new bike himself. This is a very interesting method of bike fitting.

So what are the drawbacks of this method? One for sure is the 'fit bike' itself. The 'fit bike' Dan used at the clinic costs close to 5000.00 dollars. That is quite an investment. Not many bike fitters have these. This of course limits the possibility of a local bike fitter being available with this tool. Another drawback was that for the most part the people at the clinic already knew what a good position feels like. Can we trust a total beginner to know what feels right and what does not when riding the 'fit bike'? I suppose if the position does not look good or it does not measure right we can look for some rational. There is that art thing again. Dan also mentioned that sometimes really talented riders are real difficult to fit with this method. They can ride anything. “Oh yes it feels great.” They will say that to just about any bike position.

So a few weeks ago I get a 3D bike fit that pushed me forward and over the bike and now I come to this clinic and I choose a position that is even further forward. Which one is right? I am going to have to be the judge. For now I will try the new further forward position and see how I do. Right after the clinic I was sick and only rode once on an old bike on my trainer. Since then I have ridden the bike three times, the position seems to be very aerodynamic. That is for sure. I feel more powerful on the bike and it seems like I can hold the aero position comfortably. On the negative side I do not think my pad position is quite dialed yet. I seem to tire on my forearms and my shoulders. I have not had time to change the pad position but I will concentrate on that. Finally since the position feels powerful I am feeling a bit sorer after my rides. I am feeling that as I ride this position longer and longer my muscles will adjust. If this does not happen I may start shifting my position a bit back..

Being sick for a while sure makes accessing my new bike position more difficult. If my run and my bike is any indication then my bike is also suffering. My resting heart rate has been about 10 beat higher than normal and I am going slower on all my workouts in the same effort as two weeks ago. I think I will be back 100% next week.

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