Drive-side cup keeps coming loose....Any idea's folks ?

[Ian Raleigh]

I've been out on my Motobecane several times and the drive-side bottom bracket cup keeps coming loose.

I've taken it out twice now and on the first time i tightened it as much as i could, but it came loose again.

On the second re-install i cleaned the threads and put a few drops of thread lock on the cup threads, came loose yet again.

What you reckon guys do i go mad and thoroughly clean the threads of grease and go mad with the thread lock
and hope for the best or is there a better way of stopping a cup from coming loose.

The threads on the bottom bracket and cups are fine by the way.

Add you bit guys if you've got any top tips.......

 

[Some Guy]

Probably sounds like a bit of a bodge.. But I've used ptfe "plumbers" tape before, a good few wraps of it.

Although trying some different cups is probably the proper answer.

 

[Robbied196]

Isn't there a lock ring, or is that whats coming loose?

 

[Ian Raleigh]

Probably sounds like a bit of a bodge.

A bodge ? :evil:

I doubt it very much as i care for my bikes with love and never bodge anything.
I might try a layer of thread lock all over the threads and see if it holds.job done,
If not i'll have a go at a few drops of super glue on the threads
If it comes loose again i'll get some plumbers tape and try that.

Isn't there a lock ring, or is that whats coming loose?

The drive side is a fixed cup.

Most likely get my bodge sorted out this afternoon

 

[jCymbal]

Is it still french or already english threaded?

 

[Ian Raleigh]

Is it still french or already english threaded?

French threaded.

 

[ugo.santalucia]

Thread lock can't do no harm, will also act as antiseize. Make sure you remove the grease completely from the BB shell and threads with some petrol.

 

[Robbied196]

I've read you post properly this time

How about the old trick of locking the nut flats in a vice and tightening in with the frame? I bet you'll get at least another 1/4 turn on it than you will with a spanner.

 

[Ian Raleigh]

After a phone call to a mate he suggested too removing all the grease with petrol/thinners and giving the threads
a good coating of thread lock, then putting a pipe on the end of the BB spanner to tighten up hard.

Cleaned up the BB and re-fitted everything.

I'll leave it a day for the thread lock to harden and instead of going on the road to see if it
comes loose i'll ride my Machine[bodge] on my training rollers! Makes more sense

Heres hoping for it to never come loose again.

 

[gregs656]

Heres hoping for it to never come loose again.

That will haunt you in a years time when you fancy a new bb