I was thinking about using a U bolt. My only concern is the shifter lines (bare cable) will be stretched over the U bolt, since they're close to the tube. Plus I was examining my tube last night, and it's kind of a funky shape. At the front near the fork, it's a vertical oval, but down at the crank, it's a horizonal oval - if that makes sense. Might have a hard time getting a U bolt to fit properly there. Guess I won't know till I try though.