BB keeps loosening itself

[74dodger]

OK, So I reinstalled the BB by tightening the NON-drive side first. I noticed the lockring appears to be almost flush with the cup & BB shell with hardly any threads extending past it. Test rode about 1 mile and everything is nice and snug. I assume that was key step, to tighten the non-drive side first, but I just can't seem to figure out why this is so. Oh well.

Hope to take it for a real ride later today which will be the real test. Thanks for all of your input. Hopefully the problem has been resolved.

 

[02gf74]

Dont underrstand. So how is the drive side cup held in place?

As i mentioned earlier, the drive side, known as fixed cup, has a step that limits how far it can screw into the bb, it is done up so the step is up against the bb without any gap.

Read about it on sheldon brown, only thing different to what i said is he does not recommend using pin spanner to stop the lh cup from turning when tightening the lockring. (Worked for me) other than that we are in agreement.

Anyway let us know how it goes.

 

[74dodger]

Re:

Just got back from a 13 mile test ride and everything held up just fine.

For some reason tightening the non-drive cup first did the trick.

Thanks again, everyone!!!

 

[mattr]

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.

Nah, just winds me when people keep referring to stripped threads as "threaded".

It's almost like they shouldn't be allowed to play with anything with a thread on it......

 

[02gf74]

Re: Re:

Just got back from a 13 mile test ride and everything held up just fine.

For some reason tightening the non-drive cup first did the trick.

Thanks again, everyone!!!

Still doesnt make sense to me. If you tighten the nd cup first, how do you determine how far to screw it in?

Is the nd cup in further than what is in the photo, which would mean the drive cup cannot be fully in. If that is the case, then likely reason the nd cup is not unscrewing is because more threads are engaged, indicating the threads are worn on nd side. (And if the drive side cup is not fully in, then it may loosen and may danage threads on that side)

Btw, as someone pointed out earlier, the amount the nd cup sticks out may indicate the axle is a bit too long, are the cranks symmetrical about the chainstays?

 

[KDM]

Sometimes it's like ninja, shit just works