Hi Scott,
Many thanks for the input. It looks like I have almost a similar setup as you, albeit mine is the mechanical Ultegra R8000. Let me buy the GRX 46/30 crankset and start from there.
Richard
Originally Posted by
wgscott
@
richard.susanto @
shelbyfv
I've been using Shimano's 46/30T GRX crankset with an otherwise Ultegra (Di2 6800) drivetrain (and bottom-bracket) since the week GRX was released. I had to adjust the front derailleur to the full extent of the H-limit screw adjustment range. It works fine (thankfully, as replacing the Di2 front derailleur would have necessitated replacing the rear as well).
Check your current setup. If you can adjust the front derailleur cage outboard by 3mm or more, you should be fine. The only tool you need to take off and put on a Shimano crankset is a hex wrench. Proper torque on the pinch-bolts is important. Shimano also supplies (or sells for $3) a cheesy plastic insert for finger-tightening and extracting the crank; you will probably want that as well. Finally, you will likely need to shorten your chain one or two links.
FWIW, I've used this with both an 11-34T ultegra cassette and an 11-36T SRAM cassette. Both work well, even though my rear derailleur is conservatively rated to 32T max.