bottom bracket issue on 06 Giant DH comp

[mjacko69]

Has anyone had problems with the BBs on the Giant 06 DH Comp?
Mine feels a bit "notchy", but it's a second-hand buy so perhaps despite the bike looking almost new, it could have a bad BB. I've taken the chain-guard, cranks etc off and it feels OK. It only feels bad again when I tighten the drive-side crank that last 1/2 turn...then it goes from feeling OK to notchy.
Any thoughts?

 

[pendo]

hey ive got an 06 comp and i know wot u mean abt the last turn on the cranks it goes wierd on the bb mine went stiff and the cranks did not turn freely so i got the frame faced to allow the bb to sit properly and it all works sweet check and see if it has been done if not go and get it done it will make the world of difference

 

[blackjack]

mate this mite be a bit of a long shot but it just could be your chain is rubbing pretty badly on the plate of your chain guide. this would expalin it being free to spin when the cranks and guide are off.

 

[SPOON]

Has anyone had problems with the BBs on the Giant 06 DH Comp?
Mine feels a bit "notchy", but it's a second-hand buy so perhaps despite the bike looking almost new, it could have a bad BB. I've taken the chain-guard, cranks etc off and it feels OK. It only feels bad again when I tighten the drive-side crank that last 1/2 turn...then it goes from feeling OK to notchy.
Any thoughts?

What exactly do you mean, can you explain?
Do you mean when you spin the cranks there's a tight spot?
I.E. while you're spinning the cranks its smooth for a period then all of a sudden you hit a tight spot, then process repeats .
Is this what you mean?
Or is is it just tight the whole time you're spinning the crank.

 

[mjacko69]

Thanks for the replies so far.
Yes , the chain rubs on the chain-guide when in the lower gears, but that's another issue (dodgy chain-guide) - can anyone recommend another (not too expensive) chain guide while I am on that subject?

This problem is evident when I take the chain off totally. The cranks spin ok & pretty smoothly when the bolt is not on tight. However when I tighten the crank bolt that last 1/2 turn it almost feels like a dying BB. I can't see the crank or chain-ring touching anything, inlcuding the outer of the BB - it all boils down to how tight the drive side bolt is done up. Perhaps the inside of the crank touch the BB when it's not visible?