Originally Posted by
jajacek
carleton All true I guess. Bike fitter had very little experience with track cycling. My son was training with world champion in scratch on the same track, who told him to get track bike fit, cause he has pretty lousy position. So we aimed for best fitter in town. In general, it is very difficult to find fitter with track experience. I've spoken to my friend, whose son is a sprinter for national team about fit and cranksets. Regarding fit, his son rides Look size 58. He is same height as my son but much shorter legs and longer torso. As far as crankset is concerned, we currently have DuraAce Track in chinese bike. He recommends to keep it that way. What's your opinion? If we can choose, what lenght of the crank arm should we choose? My son was riding 52x14 in recent endurance trainings. I've spoken to our junior who was silver medalist in Omnium in European Champiosnships. He rode 55x15 in endurance events and 56x15 in 3km pursuit.
You can do this yourself following the instructions in the thread linked above.
Step 1: Find photos/videos of a top rider who has a similar body as your son. COPY his position. This is what aspiring artists do...they copy the masters until they find their own style.
Step 2. Take your photo/video findings to a fitter with a fit bike and start a relationship. This might take 1 hour or it might take 3. IT IS WORTH IT. This is like taking a photo of a haircut you like to a barber. It actually makes things easy for them.
Know that the ultimate goals of all of this are:
- Put your son's body in the optimal position to make endurance power.
- Put your son's body in the optimal position to make that power as aerodynamically as possible (even in bunch races). You don't need to go to a wind tunnel ($$$!!)...just copy the guys that went to the wind tunnel
- Find the bike that allows those positions while handling like a sports car. The keys to this are also in the photos of the pros. Note where their butts, legs, feet, head, and hands are with relation to the wheels and cranks. There are 6 fixed points on the bike: saddle, crank spindle, pedals, front wheel, rear wheel, and handlebars. How the riders butt, hands, feet, and head relate to those make the fit.
You can do all of this for whatever it costs to pay for the bike fitter's time (or simply tip him/her).
As far as cranks go, Dura Ace Track are the reference cranks. You can't go wrong with those. The key is to find the length that's appropriate. This will likely be shorter than what your son rides on the road (no hills to climb on the track). I don't know what the current best practices are for endurance riding on the track, but I do know that it's commonly easier to continuously spin shorter cranks than longer ones. Also, shorter cranks means that the knees don't rise as high into the belly area, allowing the rider to stoop lower for aero gains. But, there is a point where low is too low and the power from the glutes shuts off.