UN91 re-use question

gmtfd

Devout Dirtbag
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?
 
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.
 
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.
 
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.
 
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 .
 
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
 
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.
 
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.
 
Back
Top