I have recently finished building up my new track bike, the first bike I’ve ever built, the second track bike I’ve had so far. Before buying the first one, the notorious Dolan Pre Cursa, I went through an intensive search for information on how to fit the track bike / frame. The answer to that, like to so many other things in track cycling, seemed to be “it depends”. Depends on WHAT? While I’m still waiting for the snow to melt to get the final answer, I decided to share what I have learned so far. Here it is.
Finding the right dimensions for my first bike – aluminum frame cyclocross – started with the Competitive Cyclist’s fit calculator. It helped me in getting a better understanding of the variables in sizing a bicycle and eventually selecting a bicycle that offered the best fit. My first carbon bike, the Focus Cayo that I still have, was basically an upgrade on something I’ve learned to like. Using the experience gathered from two CC and one road bike as my guideline I came to conclusion the track frame should be pretty close to the road frame I already had. The only alteration I felt necessary compared to my road setup was a shorter head tube, that would allow a lower aero position. This I would needed for the Kilo. Looking back the conclusion back then was right on target.
What I have today should be a perfect solution for the need I had. The bike fit table here represents key dimensions, starting with the competitive cyclist’s fit calculator proposal and then lists the setups I have in the two different bikes today. I was surprised to see how close the road bike and the track bike actually are to each other, at least on paper. So what is the difference then, as there must be on? And no, if you thought the answer is the seat tube, it most definitely is not!
My answer is this: the cockpit, which allows an aero position. The picture was taken while I still had the 110mm stem attached to my track bike. In my Cayo the reach of the bars is 50mm. Alpina sprint bars pictured on the right has a reach of 90mm. Together with the 120mm stem I’ll be very close to the UCI 100mm regulation (the furthest point of the handle bar from front axel).
The drop of 160mm is also quite a bit more than what I have in my road bars. Because of the two, the drop AND the shorter head tube I’m pushing the UCI regulation (not a bad thing I believe), that basically states the section you take your grip has to be above the top of the front wheel. For this reason I still have the extra length in the steerer and all those spacers you see in the picture. I need to take the bike on the track to see how it feels and then make those final modifications to perfect the setup.
The other benefit of the short head tube is that it gives me some wiggle room with the aero bar selection, the base bar in particular, and naturally allows an aggressive TT position for the Kilo. I will write a post of that at later date after freezing the setup.
So what is the answer to “it depends”? One could list a whole bunch of things, including (but not limited to) the discipline you want to compete in, your body measures, flexibility and issues in it, personal preferences, position of the moon… I’m sure you got my point. What I ended up doing is an experience (road bike setup) based assumption, which seems to be right on target: If the road frame fits, use that as your starting point. Just look at the comparison table above. I think it is pretty clear where the difference is between the two setups.To be fast your frontal surface needs to be small. To get small you need to go low. The angles and key dimensions of the track frame will help you in doing that. To make sure your hip angle does not get too sharp you need to get your saddle forward from the optimal road position. And the rest pretty much finds it place after this. If the “it depends” means there’s a learning curve to it, then yes, maybe it does. Like everything else in life.
I hope I will make a quantum leap in top speed this season. Last summer my TT setup was something you see when older gentlemen add TT bars to their bikes to make riding a bit easier on wrists. Does that sound like a good setup for the Kilo? The sprint setup has improved in equal fashion as I have added 70-80mm drop to the equation. Now I just need to wait for the snow to melt to prove I’m on the right track.
I will keep you posted.
EDIT 23.5.2013: I switched back to the 110mm stem in my road bike. I still do most of the road miles on the hoods and while riding from the drops the 120mm felt just right, it was a bit of a stretch in the upper back when on the hoods.