BB keeps loosening itself

[74dodger]

I recently bought a Raleigh M20 with the intention of making it a reliable commuter. I've disassembled everything, cleaned and lubed it. Replaced chain, pedals & busted/rusted BB.

After installing brand new replacement cage bearing BB I rode it up and down my short street 3 times. Then I noticed a lot of lateral play in my cranks. I removed the non-drive crank & lockring, tightened the cup a bit more than I probably should and reassembled it and torqued the lockring down VERY tight. Zero play.

After testing it by riding up and down my street twice, the play is back in the spindle. What the heck? Is the BB assembly just settling in requiring brute force to be applied to the bb cup? I don't want to end up chewing up my new bearings/cages.

Any help will be greatly appreciated. Thanks!

 

[raidan73]

Re:

Probably a stupid question but it is play in the BB and not the cranks right? Just wanted to check your cranks are on tight and the tapers are good?

 

[74dodger]

Yeah, its the spindle which has the play. Cranks are nice and snug requiring a puller to remove it each time.

 

[raidan73]

Fixed cup nice and tight?

 

[74dodger]

Fixed cup nice and tight?

Not sure if this answers your question but the drive side cup is tight and giving me no problems. Non-drive side is the problem.

 

[raidan73]

It does look to me like the nds cup is quite a long way out. I would normally expect to see it a lot closer to being flush (ish) with the lock ring

 

[74dodger]

It does look to me like the nds cup is quite a long way out. I would normally expect to see it a lot closer to being flush (ish) with the lock ring

Should I just torque the hell out of the cup? Don't want to damage the new bearings. Here is another angle.

 

[74dodger]

OK, after a little research online, I think I found my dumb mistake. I installed the bearings with the cages (flat part) facing outboard. I think the correct orientation is to face the bearings outboard (using the cups for races) and the cages inboard (up against the spindle).

I just flipped the bearings/cages over. The crank felt smoother, but after a few rotations on the bike STAND, the play in the cranks is back. I'm going nuts!!!!!!!!!

Please help.

This is the orientation I used (see pic). Pic is screenshot from a youtube video (https://www.youtube.com/watch?v=VXQA4kNmhPA).

 

[hirosawa]

Re:

The way it is in the picture is correct.

To be honest, you can buy a new sealed cartridge square taper BB for £10, which puts this square in the realm of not worth faffing about with.

 

[02gf74]

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?