The pulley wheels on my 12 speed GRX got trashed at a muddy gravel race. Looking for replacements, are the 11 speed GRX pulley wheels compatible with 12 speed? I know the chains are different, but I’m not seeing Shimano 12 speed GRX replacement pulley wheels…only 11 speed unless you go with something crazy expensive with ceramic bearings.
As far as I can tell they are not officially interchangeable. No idea whether it would work ok in practice (I imagine the chain/tooth interface would be ok but might simply not fit in the derailleur).
I think your best option is to search for the exploded view of your derailleur, find the part code, and then search for that specifically. E.g. for the RD-RX820 rear derailleur, the pulleys are part number Y3JS98010 (from https://www.georgesbikeshop.com.au/wp-content/uploads/2024/01/EV-RD-RX820-5005.pdf )
Y3FW98010 is the part number you need for GRX RD-RX822 derailleur pulley wheels.
The part number differs between the 11 and 12 speed GRX . What’s frustrating is that the 12 speed pulley wheels don’t appear to be in stock anywhere in the US. Why doesn’t Shimano stock current gen replacement parts? Are they forcing you to go through retailers?
I believe they’re identical to Shimano 12spd MTB jockey wheels.
C-Bear 12spd Shimano MTB jockey wheels are a good option too.