Sram Eagle GX 1 x 12 Jockey Wheel Bearings

[DieselnDust]

Your logic makes sense to me, from a mechanical perspective. That being said, I do my own bike maintenance, and other than a small application of grease to the jockey wheel bearings, my 1x11 XX1 rear derailleur has around 7000km on it and the bearings are running smoothly, hence my original question.

 

Definitely something to remember when it comes to replacing the bearings.

 

 

 

 

Yes I agree 1x11 tensioner pulley wheel bearings lasted forever. Its a smaller wheel and the derailleur doesn't swing through as extreme a range with as much tension on it. The combination of these factors (and quite possibly lower quality bearings although I doubt it as it make more economic sense to buy millions of the same type to keep the cost per unit low)

 

Because a bigger bearing will have to operate at a much more misaligned angle from the normal running axis I have a good old laugh at the margin gains companies that advertise bigger and bigger lower pulley wheels for 1x12 MTB drivetrains. A great money making racket

 

 

* I think the pulley wheel design that Shimano uses actually originated with Campagnolo

[love2fly]

Ok, I took the plunge, only because I had a spare (used) pair of JW just in case.

 

The issue as per above is that a lot of crud gets pulled in and grass winds its way around the pivot etc.

 

I took off the jockey wheels, marking the outside of each wheel with a drop of white paint and doing 1 at a time ensures they stay in sequence.

I cleaned the JW thoroughly as well as the bushing plates/washers and the bolt.

 

I placed each JW on a flat hard surface and using a socket just smaller than the outside of the bearing and then pressed it out using a vice and a larger socket.

 

To reinsert I placed the bearings in the freezer and warmed the JW with a hairdryer.

To get things started I tapped them in with a socket and hammer and finished in the vice.

 

Yes, some material from the bead gets removed but they are sitting fine and are such a tight fit the bead is probably unnecessary other than getting them centred.

 

My top JW had the most play and thats what concerned me as that "feeds" the cassette. I compared my "play" with a 3 month old RD and mine was huge, now they are better than ever.

Don't forget to put a drop of removable Loctite on each bolt.

PS I've done about 6,000km and cleaned them once before about 4,500 km ago. Long overdue.

Edited July 1, 2020 by love2fly