Originally Posted by
Leinster
Campy do a 12-29. Everybody seems to do a 12-25, which seems odd to me, as anyone who can do all the climbing they want to do in a 25, probably wants an 11,
Hardly. If you're fit enough to not need more than 25, you should have a decent spin and not need a big gear larger than the 52x13 Eddy Merckx used to dominate the spring classics, and may care more about having a 18 cog than one smaller on the end.
I don't ride road cassettes which have any jumps bigger than one tooth through the 19 cog. In the 8 speed era that meant 50-40-30 x 13-21; with 10 cogs there's more latitude and I can run 13-26 for a better chainline on the larger cogs with the big ring or 12-23 to defer shifting up from the small ring; and with 11 cogs I'd take both with 12-25.