I noticed on a pre-ride check on Saturday that my jockey wheels were seized pretty much solid... last ride on that bike was a couple of weeks ago and very manky conditions, with sloppy paste on churned up forest roads, though bike did get a good clean afterwards.
Gravel bike which gets a fair amount of use, regularly washed and lubed (though I haven't had the jockey wheel bearings apart before) and is not quite 2 yrs old. I took the mech off and removed the pulley cover washers, cleaned and put some lube in them but still very stiff, so new pulley kit ordered. I have a spare brand new mech so popped that on as I was wanting to ride that bike on Sunday.
Will sort out the original mech when the kit arrives and it can become my spare, a bit surprised how done in the bearings had become though, and I don't remember older mechanical XT mechs having same issues ? Or maybe it's just down to the riding I have been doing, maybe I should also be regularly lubing the bearings in the pulleys, though they are just simple cartridges ?
I've done it with old SRAM cable mechs, where I have some of the spare bearings for the jockey wheels and have just replaced those only. I'm on AXS now but the bearings haven't gone yet to see if the bearings I have fit.
I just recently had the same issue with a cable GX mech. Really not very old and they'd disintegrated. Luckily found a spare bearing in a box of dead mechs and fitted that.
Whereas shimano seem to run for much longer.
You can press out the old bearings and press in new ones. NX jockeys are a decent alternative, as they use bushes and last longer than the bearing ones IMO
Try some stainless ones?
Otherwise standard are pretty cheap.
You can service the jockey wheels to get more life out of them even when they have seized
Pop off the seals and then you can remove the rubber bearing cage leaving the bearings in place
Clean the bearings and cage with disc brake cleaner/isopropyl alcohol, allow to dry, refit the bearing cage, apply some grease and refit the seals
Been doing this for years with Sram jockey wheels, i now tend to check,clean and regrease everytime i do a drivetrain clean down
Mine haven’t seized (yet) but they appear to have become very loose in a fairly short space of time. I’m tempted to replace them with some better quality ones but haven’t taken them out to work out what size I need yet…
I’ve ordered some NTN bearings in what I hope is the right size. I’ve come to the conclusion that a lot of SRAM kit can be of questionable quality. Not sure if it’s a QC issue or it’s just cheap stuff they use in the manufacture and a lot of people just accept it so they get away with it. It’s not cheap to buy though so it’s very irritating. I’ve warrantied enough SRAM stuff that it’s beyond just bad luck/bad batches…