Originally Posted by
spectastic
any sprinters here? what do you think about stem stiffness? do you worry about it? what I find interesting and somewhat contradictory is that sprinters prefer to have smaller frames to get lower, and longer stems. the smaller frames generally flex less, but the longer stems should flex more, right? so what gives?
Longer stems feel more stable at higher speeds, because they place the hands further forward on the bike. This is assuming you can move around enough to get more body weight forward also.
For stem stiffness I prefer a stiff stem but one that fits is more important.
Having said that the whole reason I went to compact bars was that I tried a set (FSA Wing Compacts) and realized that holy smokes these bars are stiff compared to my 15-20 year old crit bend bars. So I got a stem that I hoped would be stiff enough so I could use the stiffer bars.
Also smaller frames... I don't think size has much to do with stiffness, at least not in the range for one rider. I used a size M and size S Giant TCR, never really noticed a difference in stiffness. However a similar sized different bike (Merlin Ti, 55 cm) was insanely flexible compared to the size M Giant.
I did request a super short frame for me but that's because then I could have more post showing (and the top tube would be below my knees most of the time). Seriously though it was more so the bike would feel more throwable while I was out of the saddle, not for any other reason.
Size is more a fit thing. Small frames allow bars to be placed lower due to typically shorter head tubes, which I find conducive toward better sprinting out of the saddle. If I never sprinted out of the saddle a higher position would be fine, but out of the saddle the lower drops is critical for me.
One of the interesting examples of custom fit is Benatti's bike when he was with Liquigas. It was a 52 cm Cannondale with a 58 cm top tube. I actually tried (very lightly) to get one for myself, although a 50 cm with a 57 top tube would be better for me. I figured if they were making a bunch of 52x58s maybe I could buy one. No such luck.