Last weekend bought a Miyata Triplecross that started talking to me at the bike swap. I liked the cross config and it was telling me to bring it home and overhaul. Much to the chagrin of my girlfriend, I did. My main commuting and training ride is a 1981 Miayata 710. I added the triplecross because I thought it would be able to bomb around the city with it, going places I wouldn't dare with my roadbike. The bike has 700c wheels, cantilever brakes, an HG freewheel, with exage hubs.
I am 210 lbs.
First test ride I was doing some rough terrain in my alley and all of a sudden my tire starts rubbing on the chain stay periodically. I take off the rear wheel and , behold, the axle is bent and breaks when I'm undoing the hub locknut. My friendly LBS sells me a bare axle and I rebuild the wheel.
Second ride, a commute to work. Bombing back to my house I brashly drop a 4" curb and, to my surprise, I have bent the new axle in exactly the same place.
My new bike is telling me I need to lose weight.
Seriously though, can I just buy a cassette 700c rear wheel and expect this problem to go away? Could I use a MTB wheelset on this frame? I can provide more exact measurements at home.