If you can flip for it I hear the Bare Knuckle frames are pretty tough... though at 700 might be a bit high... I weigh around 250 and certainly test frames' limits... I recently got an aluminum frame with carbon fork (something I never thought Id do) and I have to say it feels more solid then any steel I have ridden to date. As Carleton and many others pointed out to me, and some on the Clydes forum too, that its not the material its the design of the frame and aluminum track frames are built with be powerful dudes like us in mind. I can say I dont know if I would trust an AL road frame under me though LOL! I will also say this, I have 2 friends who have snapped/wrecked their steel frames. So its not invulnerable...