Oh, I'm not saying it's impossible to be fast on a mountain bike; I'm just saying that for any given person, it's highly unlikely that they won't be faster on a roadie than an MTB. I've only ever met one person on an MTB that I couldn't just blaze past, and his legs were spinning REALLY fast in that short top gear. I *did* pass him, it just was by like 1 MPH instead of the usual 5+.![]()