Bicycle Mechanics - 109.5mm Bottom Bracket?

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BudFox1

09-19-06, 04:04 PM

I have a 2005 Lemond which is supposed to have 109.5 bottom bracket. My current BB, which is frozen to my frame, is an ISIS drive BB. I have can not find an ISIS in 109.5mm.

My question: Will a 108mm BB work?

tomacropod

09-19-06, 04:32 PM

109.5mm is a common Shimano Octalink bottom bracket size ...are you confusing the two systems?

switching to a 108 from the intended 109.5mm will give you a 0.75mm reduction in chainline and crank/frame clearance. Not too much.

- Joel

DieselDan

09-19-06, 04:39 PM

A 110mm would be a closer match.

BudFox1

09-19-06, 04:51 PM

It's definitely an ISIS BB. I'm just not sure what size it is. But the Lemond websize states that all their bikes use a 109.5 English BB.