Originally Posted by
Maelochs
I have a clone of that model R5 .... and it fits fairly beefy 28s (I think 22-mm inside rims?) and there is enough room I wouldn't worry. best thing, of course, is to measure.
This.
I had an R3. It fit 23s, 25s would have rubbed (which means eventually sawed into the frame). This was from a long time ago (7 years?) and newer Cervelos come with 25 mm tires. (I don't think they've been making the R2 that long, though?)
Also no matter the size of the tire itself, the rim you put it on has a lot of say in how wide it actually is in practice.