BB keeps loosening itself

[legrandefromage]

tighten the non drive side cup first, hold it with the tool then attach lockring - tighten lockring.

 

[greencat]

I wonder if the lock ring is cross threaded or possibly left hand side threads in the frame. The threads in an on-one frame I had simply rusted out in the space of one winter - and the left hand BB cup just kept slipping out.

+ 1 to fit and forget cartridge BB. Could save you a tenner's worth of time trying to troubleshoot this.

 

[mattr]

Threaded? It's threaded from the factory.

You mean stripped.....

 

[02gf74]

^^^^^ yeah, i dont know what he is on about either. I doubt the non drive side is LH thread.

My money is on the o.p. not holding cup whist doing up the lockring. The lockring pulls the cup threads against those in the BB so the friction between the two stops the cup from unscrewing.

Or the threads in the frame are worn.

 

[74dodger]

Bearing orientation is correct.

Its strange that the bb loosens on a BIKE STAND!!!
When you say loosen, the lock ring has undone itseft causing the lh cup to undo?

You tighten the lh cup with pin spanner until play is gone rotating the spindle to account for any unnevenness. THEN HOLDING THE LH CUP WITH THE PIN SOANNER you tighten the lock ring?

You are packing the bearing cage with grease.


Ps who won eurovision last night?

Plenty of grease in the cages & races. The lockring is on tight, the cup seems to be the culprit. One thing I have not done is hold the cup in place while torqueing the lockring down. I didn't see this being a problem as worse case, the cup would be tightened a bit more (both are right hand threads).

I'm going to reassemble everything and mark the cup and lockring location with a drop of paint and a drop on the BB shell. Then I will compare what has loosened/moved.

I don't watch that TV show, can't help you there, sorry. Thanks for the help, really appreciate it.

 

[mattr]

I wonder if the lock ring is cross threaded or possibly left hand side threads in the frame.

Sly edit there. .......

 

[74dodger]

^^^^^ yeah, i dont know what he is on about either. I doubt the non drive side is LH thread.

My money is on the o.p. not holding cup whist doing up the lockring. The lockring pulls the cup threads against those in the BB so the friction between the two stops the cup from unscrewing.

Or the threads in the frame are worn.

OK, so the two suggestions are to hold the cup while tightening the lockring and as legrandefromage said, tighten the NON-drive side first. Sound about right? Gonna give it a shot in just a short while.

Thanks!

 

[KDM]

Re:

Just a quick question, have you another set to try?

 

[greencat]

I wonder if the lock ring is cross threaded or possibly left hand side threads in the frame.

Sly edit there. .......

Good job I have you hanging on my every post eh, mattr.



I'm sure I'll type threaded rather than cross-threaded a few more times before you cure me of it.

 

[02gf74]

^^^^^ yeah, i dont know what he is on about either. I doubt the non drive side is LH thread.

My money is on the o.p. not holding cup whist doing up the lockring. The lockring pulls the cup threads against those in the BB so the friction between the two stops the cup from unscrewing.

Or the threads in the frame are worn.

OK, so the two suggestions are to hold the cup while tightening the lockring and as legrandefromage said, tighten the NON-drive side first. Sound about right? Gonna give it a shot in just a short while.

Thanks!

As i recall, and it has been many years since i used thiz type of bb, the drive side cup has a step so is done up untol thd steo touches the frame. It had to be done up first otherwise how can you guarantee the drive cup is fully in?

If you are doing up the lockring whilst holdkng the cup, the threads on bb are gone.