So my xt 12 speed has been getting stiffer and stiffer to change gear on (shifting down to an easier gear) so I decided to give the mech a service. It’s not even a year old – maybe went on towards the end of the summer 2020.

Firstly the spring area between the back of the clutch and jockey cage was disgusting. Full of dust / mud / rust pretty much. Taken that all sort and cleaned it up / greased it so that’s sorted.

Clutch seems to be clean / as it should be so not done much with that.

The top jockey wheel is massively notchy. Taken the cap bits off and it’s genuinely the bearing itself that is the issue – seems very similar to how my gx 1- speed jockey bearings expired.

Can you get replacement bearings to press in or is it new jockey wheel time? If the latter has a lower model like slx or deore got bushes instead of bearings – if so I might go that route. It’s exactly what I did with gx – I replaces with NX jockeys with bushes and no further issues since.

No availability at present due to demand/supply issues.

XT set are part no Y3FW98010
SLX/Deore set (bushings rather than bearings) are part no Y3FY98010

Pop the seals off, clean with disc brake cleaners and regrease the guide pulley bearing – should get some more life out of it if it’s notchy rather than seized.

I haven’t got a pick so I might get one of those to help remove the bearing seals without damaging them. Guess a clean then ram them full of waterproof grease should do the job. Bit disappointing lifespan though – think at some point I’ll get the bushed deore / slx jockeys. Thanks!

No worries – mine are still going strong after 18 months in the piss-wet west of Scotland, so guess you’ve been unlucky?

Thing is with the bushed ones – IME – like the SLX/Deore is they don’t last as long as the XT bearings and the teeth wear quicker.

Thing is with the bushed ones – IME – like the SLX/Deore is they don’t last as long as the XT bearings and the teeth wear quicker.

Ah. That’s not good news either then, not that I’ve found any in stock in the U.K. at a sensible price anyway.

Wonder whether to look at aftermarket versions and see if the bearings are better quality in those.

I’ve ridden the bike all through winter so it’s got slop covered a lot – but then you’d think the lower one gets a harder time than the upper one – and the lower one is ok.

I don’t get why the teeth would wear quicker on the bushes version – you’d think the plastic material would be the same?

Bearing versions repacked with waterproof grease are the longest lasting I find. That’s the only configuration where they regularly last long enough to wear out the teeth.

I noticed I seemed to get through the first top jockey wheel on slx 12s quickly- nothing was worn but it seemed to have enough slack in it that shifting had gone to pot. Changed it out and immediately better.

@sillyoldman

No worries – mine are still going strong after 18 months in the piss-wet west of Scotland, so guess you’ve been unlucky?

🤷‍♂️

I’m in Bristol and it has been a proper wet muddy slog since about September / October and the bike has been through it all. I don’t always wash the bike after – but I do mostly clean the drivetrain with mucoff / a brush and clean the chain, then lubricate it all again.

Maybe it’s just bad luck.

I noticed I seemed to get through the first top jockey wheel on slx 12s quickly- nothing was worn but it seemed to have enough slack in it that shifting had gone to pot. Changed it out and immediately better.

Yes, found this as well. Couldn’t work out what was going on to begin with as worn 10 or 11 speed Shimano jockey wheels didn’t make much difference to shifting. But it seems to for 12.

Bearings last longer than bushings in my experience. But had to get SLX ones with bushings recently from Bikester as that’s all I could find at the time. Annoyingly Bike24 have loads of XT ones at a sensible price but still not shipping here. Did look at Superstar but a bit pricey. Wouldn’t worry too much about being notchy. It often smooths out again with more riding unless it’s really knackered. Play is more of a problem.

Bikeinn have some.

This link is Amazon but they come from BikeInn. I ordered some last week and they arrived yesterday…

Shimano Spares Unisex’s Y3FW98010 Lighting, Black, One Size: Amazon.co.uk: Sports & Outdoors

Weirdly i posted similar, 6 month old XT mech, the jockey wheels finally gave up, one was wobbling and then the other seized up today, was thinking of putting new bearings in, but on putting the new jockey wheels on i noticed the old one are pretty worn, the 13t XT jockey wheels don’t seem to be built to last!

Having a look around, superstar components do some with stock, might get them, 30 quid, but aluminium might wear a little better, making new bearings an option in a while

As I said in the other thread, I replaced the ninja throwing stars on my 12 speed SLX mech with some cheap-arse ebay aluminium things. Less than 8 quid for the pair. I couldn’t find Shimano jockey wheels in stock in the UK.

I’ll be surprised if I get anything like as long out of them, but they’re cheap enough not to worry about and the mech only has to last until August.

Firstly the spring area between the back of the clutch and jockey cage was disgusting. Full of dust / mud / rust pretty much.

I took a look at mine (SLX) for the first time in a while, and it’s clear the sealing isn’t as good my 11 speed stuff. Spring was very rusty, and couldn’t get the axle unscrewed out of the little sleeve it sits in, which doesn’t bode well for it lasting much longer…

I took a look at mine (SLX) for the first time in a while, and it’s clear the sealing isn’t as good my 11 speed stuff. Spring was very rusty, and couldn’t get the axle unscrewed out of the little sleeve it sits in, which doesn’t bode well for it lasting much longer…

This is my first Shimano mtb mech in many years – I’ve been Sram 10 and 11 speed up until this one on all my modern mtbs. I hear reports of Sram going baggy quicker and I think my X9 mech was going that way, but gx 10/11 speed was great.

I guess I’m just periodically now going to have to pull the mech off and regrease the jockey cage axle / clean out that spring area to keep it running. Never done that with a mech before but 🤷‍♂️

Shifting still hard with the clutch off?

Not quite as hard but still way harder than I remember it being at the start / then my gx 11 speed which is like pushing fluffy clouds.

I’ve just stuck it all back on in my lunchtime after servicing it and it’s improved. Fitted a new inner cable, and the various servicing bits I’ve done. Gx 11 speed still feels way nicer but it’s no acceptable at least. The GX on my other bike has just been sold on eBay so I’m putting on GX Eagle for the wider range – will be interesting to see how it compares to the xt.

@joebristol my XT clutch mech was sticky so I followed the process on this video to rebuild and lube it.

The spring was rusty and the axle was also badly corroded and I had to tap it out with a rubber mallet. I then put it in a drill and cleaned it up with Autoglym metal polish. The mech is now shifting nicely.

Could try lubing inside the shifter mechanism? That’s where a lot of the friction is with Shimano. IMO their shifter feel peaked at 10 speed. Since then they’ve been adding artificial friction and clunkiness in an effort to become more like Sram used to be. You can really feel this in XT and XTR most. Lots of praise heaped on Sram shifters for their clicky/mechanical/manly feel a few years ago. Ironically Sram have since toned it down a bit.

Shimano clutch breakaway force sometimes increases over time as the lube wears off, so maybe lube and adjust that if needed.

Yeah I followed the guide from gmbn and lubed it all up with waterproof grease. I didn’t take the pivot bit out entirely though – just cleaned it in situe – seemed to be spinning ok by the time I finished.

The shifter feels ok when not attached to the mech – both levers moving pretty freely and the cable going smoothly through the outer – the resistance is all in the mech I’m sure.

I wonder if 12 speed just asks a bit too much of a rear mech with the range 10-51. Guess I’ll see how the gx eagle goes – if that disintegrates or rusts up then I have my answer!

My finest Chinesium monkey metal pulley wheels lasted three months…

Does anyone know of a shop with the XT 12 speed jockey wheels in stock?

Superstar has their 12 speed shimano in stock, never used them though.

Apparently almost all of the shimano jockey wheels are made in malaysia, so the shutdowns there will have a big knockon effect

I went for ebay specials, also available on amazon, work well and do the job pretty much the same, glad i gave them a try and saved a few quid for once

I greased mine up and they’re still just about going. Can’t decide what aftermarket jockey wheels to try – and baulk a bit at the price of the things too.

I’m experiencing with the 12 speed bushed ones that they need stripping, cleaning and greasing more frequently than I expected. I don’t remember this with old ones but mine squeak once dry and I eliminated various other possible causes before I thought of the bloody jockey wheels. I might buy some superstar ones. Deore mech also has pivot play after only a very short life so far. A bit disappointing I think.

I had to replace the jockey wheels on my OHs slx 12s mech far before they were worn out because the bushes had so much slop it was screwing up the shifting. I wonder if it’s because the bigger size means the same amount of slack at the axle = more slack at the teeth compared to an 11t one.

I’ve been largely in the camp of getting ones with bearings and filling them with proper waterproof grease and this has reinforced that.

To be fair mine are a couple of years old and still doing ok, not done mega miles though (slx bushed).

just had a look at my SLX 12 speed mech on my Rise. 4 months old with 742 km on it. The teeth on the lower jockey look fine but half the balls in the bearing had broken up and the rest fell out when I removed the single seal that was still in tact. Useless quality. I have pressed an old bearing out of a worn out 10 speed jockey in there for the moment until I source a new wheel.

My chain was also well past 1.0 on the stretch-o-meter and I would say only 150 of those km have been in wet/muddy conditions. Pretty poor quality from Shimano. Not impressed.

@welshfarmer What’s the bearing size? I stuck a pair of SLX into my XT mech before this weekend and had to listen to weird squeaking in the big sprockets all the way around the Jennride, so I’ll probably press a new bearing into the old ones.

I would have to check. If I had to guess (I only took one measurement with a ruler!) I would say 16mm OD, 5mm ID and 5mm wide

The shifting went to pot on my Rise last weekend-in the middle of the block it was clicking and ghost shifting . Over 2000km on the chain but my chain checkers (Shimano and Park still seemed to say it’s ok. I was going to change chain and then cassette (and check the hanger)but maybe I need to be looking at the mech.

SLX, XT, and XTR 12 soeed jockey wheels all in stock with supplier now.

Just fitted some Nukeproof jockeys to the other half’s SLX mech, took a punt for £15. Seem decent quality and the shifting’s improved, which wasn’t hard as the lower bushing was completely shot!