I have one that replaces the U Bolt bottom bracket. Easy fitting and does what it should. Got mine from SSL.
Thought that it was a better option than the spring clamp method.
That's the one im thinking of getting. Was the u bolt bottom bracket under any tension or is it just bolt off the old, and bolt on the new?
Shouldn't be. The axle is resting on top of the spring, so as long as as you jack the rear up on the crossmember, the weight on the axle will be on the spring not the clamp so just bolt off, bolt on.
