I recently upgraded my Foundry Overland with a full Shimano GRX RX820 2×12 groupset and after several rides I'm feeling regrets. This is the standard 48/31 11-36 set. I used the 11-36 for a bit and I really needed a lower gear. I have a (so far undiagnosed) leg condition where I have extreme leg fatigue all the time.
After countless searches I was lead to this video where an 11-40 cassette is successfully used. For some reason I decided to order this 11-51 from aliexpress. The RD seems to handle the size, but it can't adjust properly for the entire span. If I get the higher gears to shift, the lower ones do not, and vice versa. As goes with aliexpress, descriptions are terrible and I see this says "mtb" so perhaps I ordered the wrong one. But if that is the case, it should not have fit on my hub.
I think I've found all of the discussion where mixed results are experienced with installing a bigger cassette on the RX820 2×12. I decided I'd make a new post to see if there are any ideas or success stories.
If anyone had success with an 11-40 or 11-41 can you link which one you bought?
What are my options for a smaller chainring?
Sincere thanks for anyone who has any information.
by jasonumd
3 Comments
No experience with cassettes larger than 36, but the Specialite X80 GRX chainring w 28 teeths at the front fits well.
it should work with 11-40 without issues.
Im sure you can get smaller chainrings aswell if thats not enough. I believe there will be the option of going 30-46, and if you found a 29 small ring, your derailleur could handle it aswell with the 46.
Aside of that, try using chat gpt for such things. Most of its responses will be taken from reddit database anyways and it does it in a usefull way
I only have experience with the GRX400 and it works fine with up to 11-42 (Shimano) cassette with no extenders (wolf tooth goatlink or whatever). Have also used a Sunrace 11-40t with no issues previously.
This is with 46/30t upfront.
I think the 820 is pickier perhaps? I can’t imagine 11-51 would ever work on 2x GRX!