UN54 BB fitting help please

jamabikes":en4cx97b said:
doesn't really matter but sometimes i find it easier to thread the plastic collar in a few turns to align the main body.

there are two main sizes of bb 68 and 73mm so chances are you have a 73mm bb in a 68mm shell.






I have a 70 :shock:
 
In hindsight maybe the link to the CRC one isn't that helpful :?
Here's mine - there's no 'E' in the part number
I'm not sure the 'e' in 'singapore' is valid to denote E type front mech either :D

I'll fit it how it is, and suggested as being OK by the other folk on the thread and keep a careful eye on it

I'll report back in a few weeks

P1010039.jpg
 
I still think its okay after seeing those photo's. The gap looks about the same as all of the ones I've ever fitted to my bikes; UN52's too in the past.
 
If it was an E-fit bb, it would say UN54E. That isn't an E-fit.

Always screw the drive side in first and make that tight.
I personally feel that plastic adjuster cups are better than metal as they do the job and they're less likely to sieze, although obviously you should still use anti-sieze (not grease, which is a feeble anti-sieze).
It is reassuring if the non-drive side adjuster won't go flush to the bb shell - if it goes flush against the frame, you can't be sure it's tight against the bracket itself.
Having said that, I have no experience of EBB setups, although I don't see why that should make any difference to what I have said.
 
We_are_Stevo":2svon9y1 said:
If you have a spare spacer knocking around just slip it on the drive side before you fit it?

Don't do that, it will move your intended chainline outwards by the width of the spacer. As long as the DS flange is tight up to the BB shell and the NDS cup is tight it doesn't matter if there is a small gap on the NDS.
 
Oh and just for the record I accidently bought an e-type shimano BB years ago. I had to fit a 3mm spacer on the DS to get the correct chainline and the NDS cup still had a small gap. I later (years later) replaced it with a normal UN54 of the same axle length which didnt require the spacer and guess what, same size gap on the NDS ;) . That bike does around 4000 miles a year and the BB has never come loose.
 
Anthony":1vt2i0x6 said:
If it was an E-fit bb, it would say UN54E. That isn't an E-fit.

Always screw the drive side in first and make that tight.
I personally feel that plastic adjuster cups are better than metal as they do the job and they're less likely to sieze, although obviously you should still use anti-sieze (not grease, which is a feeble anti-sieze).
It is reassuring if the non-drive side adjuster won't go flush to the bb shell - if it goes flush against the frame, you can't be sure it's tight against the bracket itself.
Having said that, I have no experience of EBB setups, although I don't see why that should make any difference to what I have said.

Couldn't have put it better myself :cool:
 
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