Hi all,
Is it very common for athletes who have dedicated road bikes to downsize to a size smaller for their dedicated TT bikes? I think I read a while back on these formus that Cancellara rode a P3C that was a size or two smaller than his road bike. What is the reason, aside from reduced frontal area and lower weight? I would think a size larger would offer a longer Top Tube length to get the rider’s back flatter…
Smaller is common. Stretching out isn’t the way to get a flat back, more saddle to bar drop is. TT bikes generally have much shorter head tubes than road bikes. Further, some use the Look ergo stem to get even more drop and change the length at the same time if needed.
I’m 3cm size smaller from road bikes at 59cm c-c to my 56cm P2C. I’d probably ride a 58cm in a Cervelo road bike, but I don’t own one (yet…)
It’s most common to drop down one size - but this will be less so with shorter riders. They may ride the same size. I note my wife is 5’6" and she rides a 51cm road bike and her tri-bike is also 51cm. I ride a 58cm Cervelo road bike, but if I was riding a P2C, I most likley would be on a 56cm.
Cancellara is also riding under UCI guidelines regarding saddle position (5cm behind BB), and Cervelo bikes are relatively longer in “reach” so it would make sense for him to size down. Torso length also comes into play as well (edit: and the sizing of the individual bike.
I have shorter legs and a relatively long torso, I ride a 52cm Cannondale road bike with a 11cm stem. Because the Cannondale Slice is relatively short in reach and I ride quite steep I went up to the 54cm with a 10cm stem and used a Ritchey adjustable to get the bars where I wanted them. In a Cervelo I would ride a 51cm.
Kevin