|   Bottom Bracket Mystery | Gerard
Sep 27, 2001 5:02 PM | | This is driiving me nuts...I just replaced my Shimano UN-71 68/110mm bottom bracket with a UN-72 68/110mm. For some reason it does not fit. My granny ring is now rubbing against a pivot point on my Amp B4. What's the deal? Aren't these supposed to be the same. Are the UN-71 and UN-72 that different? By the way, I have Sugino 900 cranks. Any ideas? Pleae help....Thanks, G |
| re: Bottom Bracket Mystery | sheebo
Sep 27, 2001 9:59 PM | | I'm not sure of any difference's between the un71 & 72, but it sounds like you will need a 113mm spindle in order to push that granny out. Could be your crank arm is setting further in on its new tapered mount. This might be due to either a worn driveside crankarm, excessive torque while installing the crankarm bolt, or slightly different spindle on your new BB. Hope this helps. Peace. |
| re: Bottom Bracket Mystery | paul.b
Sep 28, 2001 6:54 AM | | I just replaces my BB with one the same size as the old one and found a similar, though not so extreme, problem. The crank arm sat closer to the frame on the new one. Of course I didn't find this out until I approached a steep section and couldn't drop into my granny gear. A quick adjustment and I was done. For you, a longer spindle may be in order. |
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