Help sorting my bottom bracket nightmare

[andy.l]

Get a decent machine shop to make you a cup with the correct screw cut thread?

 

[development_cycle]

had thought about machining a new cup, but erm, that won't be cheap will it? And I have no idea of where to go for it either. Yell.com I guess??

 

[kaiser]

Totally wrong end of the stick :roll: for some reason I thought you had a frame with 2 l/h threads

 

[andy.l]

Got a pic of the cup at all?

 

[bushpig]

I'd consider a Mavic bottom bracket. A little heavy but very smooth and stiff. If it fits in your shell, you need to have a special 2.5mm bevel cut on either side of your shell, so your messed up threads will still be usable.

 

[dbmtb]

Yeah but no but yeah but no...

This is the guy needs a 109mm XTR BB right?

Mavic BB was never available that short
Plus sits better if bb shell is prep'ed with a chamfer for the lockrings.

Best advice I can give is

"get a UN52 while you still can (they are dropping them for ´09) and make do until you find something better the right size"

 

[bushpig]

They came in 114 and since you can adjust the chain line you should be fine.

By cutting I meant chamfering (just wanted to stay away from the term people might not be familiar with).

 

[dbmtb]

See other thread about too wide BBs....
114 down to 109...
That's 2.5 mm on each side.

Even assuming that adjustment is possible (as the lockrings are about 3mm wide), he'd have to push it 5mm over to the left to achieve correct chainline.

Horses for courses... it's just about doable, but I wouldn't.

 

[bushpig]

Well, the UN-91 i.e. the XTR bottom bracket, came in 107 and 113 so I'm guessing 113 was deemed to work

http://www.bikepro.com/products/bottom_ ... un90.shtml

 

[dbmtb]

Yes I know (I hang my Middleburn RS3s off a 113mm UN91 on my Dave Yates) but that's still a whole half millimeter on each side and ....

OK fair point and I'm taking the rag. :twisted:

My point was really that the adjustable chainline thing is there, but shouldn't be used for turd polishing.