Just completed one of the bigger gravel rides in Northwest Arkansas, over 4,100 feet total ascent. Good times. But I think my 42T big cog was getting maxed out for my ability. A google search suggests it is possible, but with trade-offs, to upgrade to a 46T rear cog.
Bike details:
2021 Specialized Diverge, 40T single chainring, GRX RX817 Di2 rear derailleur, currently using a Shimano XT CS-M8000, 11-42T.
What is the current thinking on upgrading to a 46T? Apparently, Shimano rates my derailleur to 40T officially. Obviously, bike manufacturers are going to 42T. What are the trade-offs? Shifting precision and dependability? There is mention of adding Wolf Tooth "goatlink" and certain types of chains. What success have users had with this?
by Velocybirr
8 Comments
It maxes out at 42. You will need to consider a mountain bike derailleur to go any larger
I’m running the RX812 with 46T and it works fine, you only have to fiddle with the height adjustment.
Capacity is stated as 31 teeth, so 11-46 is well above that, which an extender would not fix.
Have you considered a smaller chainring? That will work for sure. I put a 36T chainring on my bike at the beginning of the season as it’s been years since I did any hard riding, and my nearby rail trail has one steep little hill where they had to detour around a collapsed roadway cut.
I made the jump and put in a Gabaruk 11-50 cassette with their long cage and pulley wheels on a GRX Di2 system. Works great and I now have the bailout gear I need on the super steeps. It’s a little pricey, but (maybe) cheaper than and new derailleur, cassette, chain ring, etc.
Could work. But it has to be set up by someone with some elbow grease.
And most likely you will need to add one ful link to the chain.
If the GRX derailleur can‘t handle the 11-46, you could swap it to an XT DI2.
Thanks for riding with us out in NWA! Hope you had a terrific time.