the thing is, i've just fitted a new freehub body and cant seem to pedal backwards while freewheeling?? have i over tightened freewheel body? help!

What hub? Have you forgotten to put the little washer in. Why didn't you test it in your hand before putting it on the bike?

What hub is it? If it was a dragging freehub it would pull the chain off even when your not back pedaling, so I'd be more inclinded to think its worn chainrings or the freehub/cassette binding onthe frame if youve got it on completely wrong?

You should avoid back pedaling anyway, it tends to derail the chain into the wrogn gear causing to it skip/jam when you pedal properly again.

Just a guess: It's a ProII and you missed the little spacer out, or haven't seated the seal properly.

If not, more info needed please.

the spacer is there and the seal is seated,when bike is free standing and i pedal backwards manually,the casette doesnt move so the chain just gets sucked,yet if i undo quick release turn bike upside down and pedal backwards all is well.CONFUSED!!!

its a shimano m525 hub.

Is it dragging against the hub or the frame?

If in doubt take it all apart again and rebuild it with the shimano exploded diagram in front of you.

Have you definatly bought the right replacement freehub? The smimano ones all look the same externaly but are diferent sizes inside.

its deffo the right freehub. maybe it just needs running in as its new if that fails i'll take it apart and start again as suggested. thanx guys.

Maybe it just needs to bed in abit