I would like to get a GRX crank and use my left Stages XT power meter with it. I've found I can't use the XT arm with a road crankset, the width of the XT arm is 5mm wider than that of the Shimano road cranks and the bolt won't reach the interior of the spindle. Anyone know if the GRX cranks are sized like road or mountain cranks? Thanks.
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Re: Shimano GRX and XT Power Meter [offpiste.reese]
[ In reply to ]
GRX are road cranks. Which makes sense, since it allows for mtb like gearing on a Road bike
Re: Shimano GRX and XT Power Meter [offpiste.reese]
[ In reply to ]
I don't fully agree with the previous poster. GRX cranks are somewhere in between Shimano's road and boost spacing in terms of chain line. The chain line has been moved out 2.5mm on GRX relative to the road resulting in a total Q factor of 151mm vs 146mm on the road and 176mm on MTB. The BB hasn't changed so I suspect the crank arms have in fact gotten wider along with the cranks spindle relative to the road. I suspect this leave GRX crank compatibility on no-mans land but I am not sure the of the tolerances involved and you may just get away with an XT arm on a GRX crankset.
Re: Shimano GRX and XT Power Meter [scott8888]
[ In reply to ]
scott8888 wrote:
I don't fully agree with the previous poster. GRX cranks are somewhere in between Shimano's road and boost spacing in terms of chain line. The chain line has been moved out 2.5mm on GRX relative to the road resulting in a total Q factor of 151mm vs 146mm on the road and 176mm on MTB. The BB hasn't changed so I suspect the crank arms have in fact gotten wider along with the cranks spindle relative to the road. I suspect this leave GRX crank compatibility on no-mans land but I am not sure the of the tolerances involved and you may just get away with an XT arm on a GRX crankset.Thanks. It would only need to be a millimeter or two on the road crank for the bolt to catch, so it sounds like maybe it would work for the GRX cranks.
scott8888 wrote:
I don't fully agree with the previous poster. GRX cranks are somewhere in between Shimano's road and boost spacing in terms of chain line. The chain line has been moved out 2.5mm on GRX relative to the road resulting in a total Q factor of 151mm vs 146mm on the road and 176mm on MTB. The BB hasn't changed so I suspect the crank arms have in fact gotten wider along with the cranks spindle relative to the road. I suspect this leave GRX crank compatibility on no-mans land but I am not sure the of the tolerances involved and you may just get away with an XT arm on a GRX crankset.I dont disagree with you main point, But grx is for 68mm bb and therefore not compatible with mtb groupsets. While It May work out, I still believe the grx is a mtb-like groupset for a Road BB