BB won't stay tight! Aaaaarrggghh

Keveo

My deore crank developed annoying amount of play, so I bought the hollowtech tool loosened the non drive side crank and tightened the preload nut. This eliminated the play completely, until 1 hours riding and the play is back! The bike is only 8 months old surely the bb can't be jiggered?!

Any help greatly appreciated

Chunkers1980

Sure it's done up tightly? You need to do each bolt a little at a time in turn.

Quite possible to toast a Deore bb in that time, especially over the winter we've had

Keveo

Yeah it's nice and tight, the play effects both sides so it isn't as if the non drive crank arm is loose. I don't have a torque wrench so can't torque to the recommended force.

I may just bite the bullet and go for something a little more robust! :roll:

bennett_346

8 months? Yeah i'll give you a hundred quid if it isn't farked.

cooldad

XTR on Ebay for £25. Will last a lot longer.

The Rookie

Try reading the post again CD.....

Describe exacyly what you did, step by step, to tighten it the first time.

Keveo

First time around I loosened of the two bolts either side of the non drive side crank, I then loosened of the preload nut completely removing it I then took the crank [non drive] off. I had a go at the bb shell to see if that was loose, which it wasn't! I then put the crank back on tighten the preload nut as tight as it could, by hand as this is all the tool allows. I then tightened both bolts up equally and the wobble had gone!

It's doing my head in now as the chain is catching the front mech every other spin due to the play!

Chunkers1980

You do not do up a preload bolt as tight as you can. Are you sure you have the correct spacers for your setup

heez29

Check spacers as above. Does any of the bolts loosen off or is there just a lateral movement?

Keveo

Thanks for the reply chaps, the Bottom bracket is the original one from new & I haven't changed anything with the setup. The bolts in the crank arms stay tight.

For the price of a new unit I'm just going to cut my loses!

XTR or maybe a saint unit?

Chunkers1980

Xtr. Saints are gold and have longer threads

Greer_

That's about the same amount of time I got out of my deore bb, on an XT one now.

Keveo

Just bought a saint unit, apparently this will fit a 68, 72 & 80mm bb.

Hopefully I'll have plenty of happy (wobble free) spinning to follow!

bennett_346

80mm BB?

The Rookie

72mm BB?

Keveo

The Beginner wrote:

72mm BB?

Clearly I meant 73mm :roll:

Chunkers1980

So what did you mean when you said 80mm then?

Keveo

By 80mm i also meant....

Shimano Saint Bottom Bracket for M815 Cranks
RRP £39.99
Sm - bb80
For 83mm Shells.
(will fit 68/73mm with modification)

bennett_346

What drew you to the saint one? The XTR would have been a better choice.

Keveo

Purely for the robust nature of the product, also the br review sold it to me. I have also toyed with the idea of running a single ring up front in the future so would go for bb mounted chain device. The extra thread in the shell on the saint unit being the advantage. Oh and the gold finish would suit my bike superbly

bennett_346

So really because it was gold

Greer_

Keveo wrote:

I have also toyed with the idea of running a single ring up front in the future so would go for bb mounted chain device. The extra thread in the shell on the saint unit being the advantage.

Any Shimano Hollowtech bb lets you do that ... even with a 73mm bb shell, you need one spacer on the driveside to fit it.

cooldad

In any event, it's the axle length that determines what you can fit. Which is fixed.