Sloping top tubes. VERY sloping top tubes in some cases. Some MTBs measure c-c (because crotch clearance is pretty important on the trail), but even if they measure c-t the seat tube is still probably shorter than on a road bike because of the slope. That's probably why the numbers on frame sizes compare the way they do.filtersweep said:Anyway, I ride a 57 Look- which is slightly larger than a 58 Trek. Any ideas why size mtn bike this translates to? 19? 21?
DIRT BOY said:I ride a 54cm tradtion roadie and a MED (49cm) Compact frame.
On the MTB side I ride either a 16.5" with a 57.4mm TT currently and my KLEIN was a 15.7" with a 55.1cm TT.
I use the stem length to adjust fit.
As I long time MTBer I would say go for standover first over TT length.
You will wnat this on the MTB side to geive the boys some room when you jump off. I like to have claose to 2-3" of room if the trails are tight and techincal. If they are faster and smoother a slighty larger frame is fine.
IMO the worst thing on a MTB is not to have stand over clearance if you bail out!
Are you looking at a HT or FS? Smooth trails or technical?
I would say between 18 -19.5" frame will do well. Then look for the TT you want and adjust with stem length.
I prefer a longer TT and shorter stem on the road, but a shorter TT and longer stem on the MTB.