Bottom bracket unscrewing

mcshroom

Bionic Subsonic
Anyone ever met this one?

My BB lock ring keeps unscrewing when I'm out on long runs. I've taken it off, cleaned the threads on the bb and frame and put back in with lithium grease but it still does it. Could do without it doing this when I go for my tour next month.

I'm thinking about finding a less good grease for the threads, or using an anti-seize but they are a bit of a step in the dark and I don't want to get it stuck in there.

Bikes a Claud Butler Hybrid with an alu frame and cartridge bb
 

Gerry Attrick

Lincolnshire Mountain Rescue Consultant
You could try wrapping the part of the thread that the lock ring screws on to in PTFE tape before installing the ring. It acts as permanently pliable thread lock and also prevents seizing.
 

swee'pea99

Legendary Member
Is this an Italian BB? They can be a bugger for unscrewing themselves. I only solved it with a big screwdriver and a hammer. If it's British, I'm baffled...they're supposed to tighten themselves as you go, not loosen.
 

TheDoctor

I've seen things you people wouldn't believe
Moderator
Location
Stevenage
Well...it can't be an Italian BB in a British frame (or t'other way about) as one of the threads would be the wrong way round, so you'd never get it in.
I'd Loctite it meself, but get advice. IIRC there's red (weakest), then blue, and finally green (never ever coming out).
 

rustychisel

Well-Known Member
Are you sure that a) the bottom bracket shell is adequately clean and faced (ie reasonably smooth and flush) and :thumbsup: most importantly, you're doing it up tight enough? The manufacturers spec for torque is really rather surprisingly high.
 
OP
mcshroom

mcshroom

Bionic Subsonic
Hi everyone thanks for all the tips.

To update I cleaned everything off and wrapped some PTFE tape on the threads before re fitting. I also used an allen key with much greater leaverage (my bb tool is allen key driven).

It's worked. I took it out for a 100km slog up some steep hills (Whinlatter pass) and it's still tight and happy. :laugh:

Thanks
 
Top Bottom