I'm looking to build up a new commuter, and I want to go singlespeed. One of the two frames that I'm interested in is the IRO Rob Roy. What concerns me about the IRO are the curved tubes for the rear triangle. I understand that they're curved to offer some dampening when it comes to road vibration, but could that be a structural weakness when combined with my weight (260 pounds) and the extra frame stress of me standing and hammering a 48/17 gear up a 3/4 mile hill for my daily commute?
I just have horrible visions of the rear triangle collapsing under my bulk, and ending up with a butt full of tire as I'm mid-way up the hill one morning.