Crankset and bottom bracket compatibility
I have just bought myself a 48/38/28 Shimano Tourney X crankset to replace the original Sugino on my Spesh Sirrus - an almost like for like replacement. The bottom bracket I was recommended was the Shimano UN-300 68-113mm (also purchased). Having looked at the spec of the Tourney crankset on the Shimano website it recommends that the BB specs should be 68-122 or 68-123. Is using the 68-113 going to make much of a difference, or should I return it and get the UN-300 68-122 or 123?
I understand that the 68 is the length of the BB, but not certain what the 113, 122 or 123 relate to. Can anyone help.
Cheers
Comments
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68 is the width of the frame where the bottom bracket attached, the 113 refers to the length of the axle. So this will mean your crankset is closer in and may foul on something or make it difficult to get enough movement in the front mech to use the granny ring. I'd try to change it for something closer to 122 or 123.
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Thanks for this. Unfortunately the bottom bracket I need is no longer available it seems (need a UN300-K LL123 68 x 122.5). Returning the crankset and potentially going to have to switch to a double chainset from hereon, meaning buying a number of other components too.
Cannondale Synapse AL 105, Specialized Sirrus Comp0 -
It's the BB-UN300-K which has space for the chain case too. It's a subtle difference but it's wider than the standard BB-UN300.
Cannondale Synapse AL 105, Specialized Sirrus Comp0
