Originally posted by Richard D
Can a UN72 be used as a direct replacement for a UN52, or are there differences besides weight?
I have yet to find a pair of cranks (including Shimano's own RSX!) that will seat fully (and what I consider properly) onto a UN-72. Therefore, the UN-72 I bought for son #1's bike (68mm BB shell width) turned out to be about right for son #2's bike (73mm BB shell width). The spindle of the UN-72 I finally used for son #1's bike is 5mm shorter than the one it replaces.
I had always heard that Shimano uses the same taper, but a larger ultimate diameter, than Campagnolo, but I really would have expected a Shimano crankset to seat properly onto a UN-72 BB!
__________________
"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069