UN91 re-use question

gmtfd

Dirt Disciple
I removed the bottom bracket from the '94 Rocky Ridge I'm currently working on, to discover it's a lovely UN91. It was feeling a bit gritty before I took it out, but feels smooth in the hand. Do people think it would be possible to re-use it, or is it a gonner after 27 years?
 

integerspin

Senior Retro Guru
I pulled a UN91, it had felt a bit metal on metaley. After I pulled it out it
felt lovely and smooth but a bit loose.
I stuck it in another bike and it felt loose, the cranks could be rattled a bit,
but it was lovely and smooth.
 

hookooekoo

Devout Dirtbag
I have the UN71 on my bike. The BB was slightly notchy after removing the cranks but with the BB still in the bike frame. When I removed the BB from the bike it was totally smooth.

After I got the frame resprayed I reinstalled the unit and it was slightly notchy again. I just backed off the cup that holds the unit in place by a tiny fraction of one turn, and it became lovely and smooth with no play.
 

Frankenorange

Retro Guru
Re:

If you are going to replace the un91 and it is for a 68mm bottom bracket please PM me with a price. If the cups are in good shape(spline and threads) i want those cups and no matter if the bearings are shot. That is if you are in the uk, of course.
 

fearfactoryüberalles

Senior Retro Guru
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Re: Re:

Frankenorange":2nq0mrny said:
If you are going to replace the un91 and it is for a 68mm bottom bracket please PM me with a price. If the cups are in good shape(spline and threads) i want those cups and no matter if the bearings are shot. That is if you are in the uk, of course.

Why don't you get a BB-UN300 instead? New, cheap, with very similar alloy L+R removable (OK, with a bit of force :twisted: ) silver cups to the UN90 series, they work on the UN70-72 series, an unlikely retro-mod godsend from the Big S these days :D .
 

Frankenorange

Retro Guru
Re: Re:

fearfactoryüberalles":11usp0rr said:
Frankenorange":11usp0rr said:
If you are going to replace the un91 and it is for a 68mm bottom bracket please PM me with a price. If the cups are in good shape(spline and threads) i want those cups and no matter if the bearings are shot. That is if you are in the uk, of course.

Why don't you get a BB-UN300 instead? New, cheap, with very similar alloy L+R removable (OK, with a bit of force :twisted: ) silver cups to the UN90 series, they work on the UN70-72 series, an unlikely retro-mod godsend from the Big S these days :D .

Thank you for that top tip. I will look into it.

Cheers
 

gmtfd

Dirt Disciple
Re: Re:

Frankenorange":36hfou5c said:
If you are going to replace the un91 and it is for a 68mm bottom bracket please PM me with a price. If the cups are in good shape(spline and threads) i want those cups and no matter if the bearings are shot. That is if you are in the uk, of course.

PM sent.
 

hamster

Retro Wizard
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Re: Re:

fearfactoryüberalles":fvwsxlm0 said:
Why don't you get a BB-UN300 instead? New, cheap, with very similar alloy L+R removable (OK, with a bit of force :twisted: ) silver cups to the UN90 series, they work on the UN70-72 series, an unlikely retro-mod godsend from the Big S these days :D .

Does UN300 have the hollow shaft like UN7x and above? I've been trying to work out how decent the new ones are, now that Shimano has killed off UN55.
 
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