MegaSack DRAW - This year's winner is user - rgwb
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Hello all,
I'm looking to fit a sub compact road crank on my original specialised diverge that has a Shimano 105 double road crank with 43.5 chain line on it now. The new Shimano GRX cranks come with a 46.9mm chain line. Will this work or would I be entering a new world of chain stretch and issues with the chain falling off when back pedalling etc...?
Anyone know?
In theory, it's compatible - but you need a GRX FD I think
No expert but should work, Shimano say u need the specific grx front mech but I’d see if u can make ur old one work with limit screws right out first
Yes, I think some people have made it work with the 105 FD (depends on the frame I guess) but it's apparently not ideal and compared with the cost of the cranks the FD is cheap, so might as well use it, Other than that it is supposed to be fine.
Swapped an Ultegra chainset for a GRX. The Ultegra FD kinda worked until an adjuster screw fell out. Replacement GRX FD works perfectly.
GRX Ft mech best to be used as it matches both the chainline and smaller ring diameters. Given that both groups are intended to work on the same 135/142 OLD rear ends,I wouldn't worry about back pedalling/chain derailing.
Thanks all. However my bike has a 130mm Specialized SCS chainline. So that places my chain line essentially 2.5mm closer towards the centre of the bike. It's purely the crank to hub centre chain line that concerns me as I'll be 3.4mm off centre.
Unless it seems I can source a stand no tubes 330 rear hub and then I can convert my wheel to run a regular mtb chain line and all would be golden.
QR or bolt thru SCS?
bolt thru 130 equivalent of 130mm spacing