BB 30 creaking

Nadirkhan

Is it possible that the BB30 bearing get oversized with time?

Because when I put the crank spindle into the bearings it goes in without any resistence which I think is the problem since it result in some play at the place where spindle meets bearing. And I also believe that is the main cause of creeking in my case.

I have bought new bearings (haven't fitted them into the shell yet) but when I put the new bearings into the spindle they take alot of effort to pass the spindle (which is good right?)

Or is it my spindle that has worn out and undersized?

mfin

Praxis adapter

Nadirkhan

mfin wrote:

Praxis adapter

Not available here and the adapter is probably not applicable to simple BB30. It is applicable to BB PF 30 I think.

Nadirkhan

Is it possible that the BB30 bearing get oversized with time?

Because when I put the crank spindle into the bearings it goes in without any resistence which I think is the problem since it result in some play at the place where spindle meets bearing. And I also believe that is the main cause of creeking in my case.

I have bought new bearings (haven't fitted them into the shell yet) but when I put the new bearings into the spindle they take alot of effort to pass the spindle (which is good right?)

Or is it my spindle that has worn out and undersized?

sungod

if the original bearings were badly fitted, or if water got into the bb shell, it is possible that the spindle may be worn/corroded

there is a process called fretting that can affect shafts (i.e, the spindle) in bearings, poor fit or very slight misalignment can damage the shaft, especially when the bearings are much harder, it can also lead to fatigue failure

it seems odd that the old bearings are a looser fit than new ones, but assuming the shaft is smooth and it's not due to crazy tolerance problems it seems a good sign - i.e. that the shaft is probably not damaged

the shaft should be an interference fit in the bearings - absolutely no play, surfaces must be free of dirt before assembly, grease the shaft and bearing surfaces before fitting, most grease will be forced away, but the thin layer between shaft and bearing will reduce the risk of noise/damage

fyi fretting damage often looks like this...

mitchgixer6

mfin wrote:

Praxis adapter

Praxis adaptor is only useful if trying to fit a Shimano (or Campag) crank into a BB30 frame. That's not the issue here.

As usual good advice from Sungod. It may be the case that the bearings inside the sealed unit have worn enough to allow the inner race to move slightly. This would account for the difference between the old bearings and the new ones.