outboard bottom bracket with too much play in it

Howitzer

Hi All,

I've a shimano outboard bottom bracket like the one in the post below.

It's got some play in it between the cap and the side. I can see it move about 1-2mm and the whole crank plays a lot more due to this.

Whatcha reckon - would a service like this below help fix this?
Or is it a symptom of worn bearings and the unit needs replacing so don't bother?

Outboard Bearing Bottom Bracket Service Guide. With Pics.

I'm surprised to be in this situation as the BB is only 1yr old and doing 16km total commute during week... 3000-4000km ish?

Advice appreciated.

kona

Howitzer wrote: »

Hi All,

I've a shimano outboard bottom bracket like the one in the post below.

It's got some play in it between the cap and the side. I can see it move about 1-2mm and the whole crank plays a lot more due to this.

Whatcha reckon - would a service like this below help fix this?
Or is it a symptom of worn bearings and the unit needs replacing so don't bother?

Outboard Bearing Bottom Bracket Service Guide. With Pics.

I'm surprised to be in this situation as the BB is only 1yr old and doing 16km total commute during week... 3000-4000km ish?

Advice appreciated.

By cap what do you mean? The Cap that locates the crank arm, the dust cap on the Shell covering the brearings?

Usually but not always its a symptom of worn bearings, Ive mine in my bike alot longer than a year and they are still good. while not ruling it out its unlikely. Most obvious would be the shells are not tight in the frame or the L/H crank isnt located properly onto the axle.

Howitzer

Hi Kona,

I mean the 'dust cap on the Shell covering the brearings' and everything below that seems to move more than it should. Should stay flush where it is from previous inspection at time of install.

I had crank and axle removed to inspect.

I'll give it a service tonight and see how I get on.
Hopefully caps come off ok and I'm not on the foot express & Luas tomorrow ;-)
Cheers

kona

Howitzer wrote: »

Hi Kona,

I mean the 'dust cap on the Shell covering the brearings' and everything below that seems to move more than it should. Should stay flush where it is from previous inspection at time of install.

I had crank and axle removed to inspect.

I'll give it a service tonight and see how I get on.
Hopefully caps come off ok and I'm not on the foot express & Luas tomorrow ;-)
Cheers

The Shimano cups are different to the one in that guide you posted. If there is no movement in the bearings, they are fine.

zil

If your cranks have any play in them at all when installed correctly the bearings are shot and you need to replace the BB.

When your installing everything make sure that the bearing preload cap is tightened, this cap should be on the non drive side crank and you need to tighten it before you do up the pinch bolts to secure the crank (make sure not to overtighten the cap, it should only be finger tight). The cap pulls the two cranks together against the bottom bracket bearings and makes everything fit together snugly. If with the cap tight and the cranks bolted down there's still play then you need a new bb, if there's just grittiness then as the article you linked says you can replace the bearings, however like it says the bearings are usually not designed to be replaced.

Howitzer

hi Zil, thanks for feedback.

I got into the bearings that eve and the non drive side (problem one) was all gunged up. I cleaned and regreased - but no joy. The pitting in the bearings was too much. So it's dead after 1 yrs 16k daily commute.

My replacement BB has arrived today.
I went with a non-shimano this time.
Token External MTB Bottom Bracket

Feels like good quality.

is it worth greasing the gap between the cap and sides during install?

zil

The preload cap pulls the side of the cranks flush with the bb and therefore the cranks, the bb surface and the preload cap should all move together so there's no need for grease there. Btw if you don't have the correct tool to tighten the preload cap a 5c coin works just as well.

You should only need to grease the bb threads, the preload cap threads and the inside of the bb and the axle. If your feeling thorough you can take off the dust seals on the bb and check to make sure there's enough factory grease in the bearings themselves as well. Make sure to double check that you've got the correct number of spacers as everything will install fine without them and you won't notice any problems till your out on the bike and try and change gears.