68mm crankset in in 73mm BB shell
11-17-20, 01:30 AM
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68mm crankset in in 73mm BB shell
Does anyone know of a special BSA bottom bracket that will allow me to install Shimano road cranks, in a bike frame with a 73mm bottom bracket shell? thanks.
11-17-20, 04:47 AM
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Is this a modern Hollowtech II crankset or an old sguare taper? If it is a Hollowtech II crankset, there is no option to fit it to a 73mm bottom bracket shell. The spindle is not long enough to be able to properly attach the non-drive crank arm.
If you are trying to put a road crank on an MTB frame, the other considerations are crank arm clearance and chainring clearance to the chainstays. MTB frames have wider stays to fit wider tires and the road crank arms and larger chainrings may hit the stays.
If you are trying to put a road crank on an MTB frame, the other considerations are crank arm clearance and chainring clearance to the chainstays. MTB frames have wider stays to fit wider tires and the road crank arms and larger chainrings may hit the stays.
11-17-20, 10:56 AM
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Putting road cranks in a mountain bike frame might impact the chain line of where your chain wheels sit going to the rear cogs. If you have a road crank what is it? Hollowtech II? You won't put that in a 73 mm shell. Octalink? Find an Octalink BB from a mountain bike group.
A Shimano BB-ES300-E has a couple versions for 73 mm shells and is Octalink. Your Shimano road cranks if Octalink will fit on them. But whether there is interference with the chain stay or it messes up the chain line because you want road cranks on a mountain bike frame, that is on you.
If you don't have the cranks already then get the correct genre of stuff for your frame.
A Shimano BB-ES300-E has a couple versions for 73 mm shells and is Octalink. Your Shimano road cranks if Octalink will fit on them. But whether there is interference with the chain stay or it messes up the chain line because you want road cranks on a mountain bike frame, that is on you.
If you don't have the cranks already then get the correct genre of stuff for your frame.
Last edited by Iride01; 11-17-20 at 11:01 AM.
11-17-20, 11:36 AM
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One possibility is to have a bike shop face off 5 mm from the bottom bracket shell, either 2.5 mm from each side or 5 mm from the non-drive side. However, that may indeed cause the crankarms to interfere with the chainstays on one or both sides.
11-18-20, 04:14 PM
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hollowtech road triple cranks can be used with 73mm bb shell and normal caps,
remove included axle spacers, and use smaller bb spacers instead
when I tried to convert my mtb bike with 63mm shell to 1x setup with low q-factor cranks,
I have found that chaistay was not compatible with low q-factor road double cranks,
but it was compatible with low q-factor triple hollowtech road cranks (with single ring)
remove included axle spacers, and use smaller bb spacers instead
when I tried to convert my mtb bike with 63mm shell to 1x setup with low q-factor cranks,
I have found that chaistay was not compatible with low q-factor road double cranks,
but it was compatible with low q-factor triple hollowtech road cranks (with single ring)
Last edited by kek; 11-18-20 at 04:22 PM.
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