I am definately in the Clydesdales category weighing in at 240lbs. I am only 5'8" (on a good day) so finding bike sizes can be tricky when looking for used. So I took my friends Centurion and fixified it. I love riding this thing and haven't been worried for a second about my weight on it. I am using 700x25 tires on Mavic Ma3's. I can haul pretty good with my 42/16 gearing, but may bump it up to a 48 soon.