bottom bracket threads have worn is it fixable

crrazzzyy

Hey guys i have a classic orange sub 5 frame im doing up but the bottom bracket threads on the bike have worn so the bb hollowtech wont screw in it just pushes in .
Is this fixable by tap and dye ing the thread or will this make it too weak ...any other options ??

Thanks in advance

nicklouse

if you have stripped the threads then there is nothing to cut into.

be aware that there were some undersize HT cups out there.

three options. cut and shut the BB and re machine, bore out and fit an insert. fit a BB that screws onto its self. these tend to be square taper fitting only.

edhornby

press fit cups for a square taper BB, you loctite them in and they never come out so it extends the useability of the frame but once the BB within it dies, the frame goes in the bin or cut the entire bb shell out and weld a new one in

I would go for the 'bore out the threads, fit pressfit bearings' option - have you spoken to BETD/Goldtec ? they would be the guys I'd go to with something like this...

crrazzzyy

Some usefull info /options there thanks guys

stubs

Dont know whether its possible but you might be able to get the bottom bracket threaded for Italian threads they are slightly bigger than the standard BSA threads and Shimano do road HT11 BBs with Italian thread. Best people to talk to is Orange.

The Rookie

Argaubly, as long as the shell is square an HT2 style BB needs no threads, it can't go anywhere, so I'd be inclined to just use some threadlock on them and install the cranks and preload before it goes off (threadlock to stop them spinning in the frame).

craker

The threads have just died on my SS bike, the bike shop tried and failed to cut a new thread. They didn't have a tool for an Italian BB thread.

So I've just installed a threadless bottom bracket

http://www.ebay.co.uk/itm/YST-Threadless-Bottom-Bracket-FOR-damaged-threads-68mm-x-116-119-or-112-5mm-axle-/190716907198?pt=UK_sportsleisure_cycling_bikeparts_SR&var=&hash=item2c679d0ebe

The guy in the shop told me I'd have to ream out the thread in my BB shell (false) and have the shell faced (maybe true). Certainly after 40 miles it had come loose, the suggestion over on yacf is that you need a bevel on the shell to stop up and down movement; I've had a go at mine with a grinding drill bit to give it a bit of an edge. It's worked so far (this morning's commute!).

I'd ignored the possibility of having a framebuilder look at as being too expensive - having spent £30 on bits to get this far it wouldn't be too much more cash for someone reputable to braze in a sleeve and cut a thread into that, though it will leave your bike with damaged paintwork.

The Rookie

BB won't work with a hollowtech crankset, and you can't braze into an Orange Sub 5 (ally frame).

No need for any faffing you describe with that BB.