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View Full Version : WTB: BB-UN51 cup(s)


oliver1850
02-28-2018, 11:08 PM
I've been trying every BB in the hoard trying to fit an antique MTB triple to a road frame. I have the guts of a 127 mm spindle UN51 that I wanted to try, but found that it's an odd diameter - off .5 mm from other Shimano BBs. IIRC the OD is 30 mm. I could use a Chorus cup for the left side, but Campagnolo uses smaller OD bearings on the right side so I still need (at minimum) a right side cup. I went through a bunch of BBs tonight. The Campagnolo cups are all too small and most of the Shimano BBs have the cup integral with the center sleeve. Don't know if there are other Shimano models that might interchange. Let me know if you have something. Thanks.

oldpotatoe
03-01-2018, 07:38 AM
I've been trying every BB in the hoard trying to fit an antique MTB triple to a road frame. I have the guts of a 127 mm spindle UN51 that I wanted to try, but found that it's an odd diameter - off .5 mm from other Shimano BBs. IIRC the OD is 30 mm. I could use a Chorus cup for the left side, but Campagnolo uses smaller OD bearings on the right side so I still need (at minimum) a right side cup. I went through a bunch of BBs tonight. The Campagnolo cups are all too small and most of the Shimano BBs have the cup integral with the center sleeve. Don't know if there are other Shimano models that might interchange. Let me know if you have something. Thanks.

UN72/91, both cups come off.