1. Santa Cruz aluminum frame, snapped a few inches above the bottom bracket, at a weld line for a reinforcement. I was sprinting and heard it, frame didn't fail/fold but felt weird, didn't realize till I looked close. SC had me a new frame in a few days after I sent pics.
2. Light weight road racing seat, I think they were aluminum rails, snapped when I leaned back on the seat, my hands weren't on the handlebars. I landed on the road on my back. No warnings at all.
3. Cannondale aluminum crit frame. Back before replaceable derailleur hangers. It snapped clean off, got a new frame for free, even asked which one and which color I wanted.
I've bent various bike parts out of steel, but never had one snap. Does seem like aluminum has a reputation for just snapping. Heard similar stories from friends, riding buddies, and fellow racers.
