Viewing 29 posts - 1 through 29 (of 29 total)
  • 12 speed shimano derailleur life expectancy?
  • peanutcracknell
    Free Member

    Hi all. Derailleur related query – how many miles do you get out of a 12 speed derailleur before the pivots are all so worn out that the thing is a ‘mere wreck’, rather than a rear mech?
    Obviously terrain, and local conditions vary, and some people may lube the pivots and some (most?!?) probably don’t, so it would be handy to know these details too.

    I’m based the forest of dean but I ride the welsh valleys a fair bit plus the bike has done a week in finale and probably 7 or 8 uk uplift days too. So I guess you could say it’s had a fairly hard life, and on top of that I don’t lube the pivots.
    I’ve just worn out another xt 8100 mech in around 700 miles with the above use (abuse, maybe?) The pivots are all really sloppy, it just about shifts acceptably in the workstand in both directions but needs noticeably more care than the deore one on the other bike and once pointed down something rough if I pedal it will be constantly changing gears on me.

    So, what do you get out of your mech? What model do you use, and how badly do you treat it?

    I feel like I might be better off just buying a deore one and changing the jockey wheels for xt items when the originals die? Or has your deore mech only managed 400 miles?

    Full Member

    Have similar issues, i think it’s all 12 speeds when ridden in pretty rough conditions, i do FoD and the local areas, uplifts and so on as well and the mech has just taken so many hits it’s sloppy, jockey wheels are fine though.

    I think SLX is the fine line for Shimano, will probably get one of those next, shifting is getting slightly poor now due to the slack, but it still works so will wait for it to snap in half like the last one!

    Full Member

    Have you tried changing the hanger? I’m not sure I’ve worn a mech out on any bike and some of them have done 10s of 1000s of miles. 700 miles is potentially a few weeks worth.

    I did think I’d worn a mech out once. I put a new one on and it was no different to the old one.

    Full Member

    Around 1750 miles in almost 2 years for my XT rear mech, used on my HT in the Welsh valleys. Still seems to be in good condition, and isn’t cleaned and maintained particularly carefully and is used through the winter

    Full Member

    Have you tried changing the hanger? I’m not sure I’ve worn a mech out on any bike and some of them have done 10s of 1000s of miles.

    This. Check your hanger alignment (with the tool, not just by eye).

    and the mech has just taken so many hits

    Same.. check you hanger alignment.

    It’s pretty much the first thing I do with any gear-related issues. 12 speed cassette sprockets are closer together so the margin for error / issue can be very small.

    Free Member

    1000km on the e bike and still going strong.

    Full Member

    Still using a 90’s 8 speed XT mech in slop on my daily commute. Just new jockeys every once in a million miles.

    Eyy by eck, they don’t make em like they used too. 🙂

    Full Member

    If the OP is having the same amount of rock strikes, crashes, crap getting stuck in it and rear mech hits you get doing the stuff around FoD/BPW/etc then it’s not a case of the mech being sloppy because of just shifting, my old 11 speed XT mech did thousands of miles commuting or XC.

    Full Member

    I managed to snap my last Xt m8100 mech when a stick jumped up at it just before Christmas. I’ve never snapped a mech before then.

    When I got a new one it feels a lot tighter than the old one – in comparison it feels quite baggy. It initially shifted better with the mew one but that’s gone already in 3 months – back to shifting like the old one was. I’d say the shifting on my gx Eagle mech has always been lighter and it’s more snappy.

    Just on the deore mech apparently the clutch doesn’t last as well anecdotally – I was out with Sam Copp having a coaching session around Christmas and his clutch essentially wasn’t doing anything – the chain was slapping around everywhere. Maybe it just needed adjusting but I think deore lacks the same adjustment that Slx and up has.

    Deore and slx also have bushed jockeys but apparently they don’t last well – previous bushes Shimano jockey wheels have lasted really well.

    So I reckon the best option in cost effective terms maybe SLX with XT jockey wheels.

    Free Member

    Thanks for all the replies peeps.

    what kind of terrain do you ride mostly?

    and @Frogstomp I haven’t checked the hanger recently, but it was bang on when I looked a couple of months ago when it first started getting bad.

    that’s interesting, I had wondered if the suspension movement would accelerate the wear.

    that’s interesting, and echoes my experiences too, they get noticeably freer after just a couple of months use.
    On the deore mechs – I know Sam, and I don’t think his bike sees much love. It gets plenty of use too. I’ve read somewhere that the clutches are the same across all Shimano mechs, except for the cover on the xt (maybe XTR too?) which has a port for adjustment. You’re definitely right on the bushed jockey wheels, the ones in my previous slx mech, and the deore mech on the other bike didn’t last much more 4 or 500 miles.
    I’m still thinking of trying a deore next, with an upgrade to xt pulleys when the originals wear out…. if the rest of the mech lasts long enough!

    Why do I have a feeling I’ve found the real reason for the parts shortage?!?

    Full Member


    You could always try a gx Eagle mech on there and see how that goes? Their weakness is the bearing in the lower hockey wheel seizing – but you can swap the bearings out for a couple of quid a time.

    Full Member

    I think you need to stop smacking it into things 🙂

    Free Member

    Not Shimano but my GX 12 speed mech has been cannibalised many times and done about 1200 miles in 2 years. It’s triggers broom but had 3 x new jockeys and swapped the cage of an old one. If it’s getting battered on a regular basis 800 – 1000 miles seems about right. My average ride length in the valley is between 10 and 15 miles so on average about 80 rides.
    I dread to think what it will be with an ebike.

    Free Member

    My 12 speed shimano mechs go pretty baggy at the pivots and creak from them in less than 1000 miles. Pretty annoying.

    Free Member

    My XTR M9100 one is bang on after 2 years / 1900km of use and nothing in the way of maintenance other than washing the bike every once in a while.

    Full Member

    Interesting, my 10 speed mechs used to last for near enough the life of the bike but since moving to 12 speed I’ve had terrible luck. Rock strikes, branches and crashes mean I’ve been through more rear mechs than cassettes! It would be nice to have one on long enough to wear it out.

    Free Member

    I don’t think i’ve ever ‘worn out’ a 12 speed rear mech, Shimano or SRAM. The one on my little bike was from the spares box & it had done probably 5-6000km & half of that was on the back of my ebike last year & it still shifts fine. It’s a bit baggy, but I find they all do that.

    Ridden in all weathers & conditions & also FoD based, so probably ride similar stuff. I’d be pretty miffed if I wore a mech out in 700 miles. I can do close to that in 6 weeks riding in the summer.

    Full Member

    I went 12 speed last year, everything is just super fussy.

    Free Member

    My 11 speed SRAM mechs seem to have a lifespan of around 2 years before they get tired and shifting goes bad on them.

    Free Member

    5000kms of Peak bashing on an XTR M9100 and still works as good as new.

    @LS likewise. 2 years ago I got my Slayer and have thrashed it, still going strong.

    Free Member

    I destroyed an xt one with a rock strike but the replacement slx has lasted very well over the last 18 months, including a hanger bending incident. I couldn’t see the benefit in the xt after it smashed and I’d definitely get slx again.

    Full Member

    I don’t think i’ve ever ‘worn out’ a 12 speed rear mech, Shimano or SRAM.

    This is my experience also. All of my bikes have been used and abused 2/3 times a week their entire lives, and ridden everywhere from the Chilterns to The Peak, Calderdale, Scotland, Wales, Lakes etc etc in all weathers, most have outlasted the bikes they were on. Current XO1 on the Enduro is 3 years old and has done 1000’s of km. Looks bashed in and there are scrapes all over it, but it shifts like it’s fresh from the factory. In fact I’ve been super impressed with SRAMs 12 speed sets, they last ages, have reliable shifts, easy to live with, pretty robust. They only bit that’s a pain with SRAM is changing the inner cable, but they’ve always been shitty by comparison to Shimano.

    Full Member

    @idlejon that’s interesting, I had wondered if the suspension movement would accelerate the wear.

    its the clutch they will accelerate mech death as it puts force through the mech. On a HT you dont get the same forces in teh mech than on a FS bike.

    12sp on my eeb used all the time was pointlessly shit – scam mechs never worked properly from new (NX and GX) shimano deore was a significant step up in performance but still a bit crap. I even bought a hanger alignment tool when i had the SRAM mechs – i`ve never even thought of owning one in the previous 20yrs biking- haha!

    The microshift 10speed i`ve put on is just a joy to use.

    Free Member

    An interesting mix of replies so far, but it seems like most people are getting, or would expect to get more than 700 miles out of a mech.
    For reference, here’s a link to a short video showing the wear I’m grumbling about.

    I got the hanger alignment tool on there yesterday, that was bang on. I also checked the B screw adjustment. This had gone out by a fair bit, I’ve loctited the screw this time to see if it stays put, I’ll add a locknut if it doesn’t.
    I’ll give it another try this weekend when the covid has worn off.

    Free Member

    I noticed similar play in mine when it was off the bike and I was servicing it thinking this can’t be right. All it needed was the lower limit screw winding in so it contacted the stopper. Obvious suggestion but have you checked that?

    Full Member

    2000km on the XT12 on my e bike and it’s still absolutely fine.

    There was another post on here a few weeks ago. 15+ years ago I definitely binned mechs due to sloppy pivots but for me that’s long stopped being an issue. Jockey wheels wear out (and that’s what goes more quickly riding in mud) but all of my recent mechs have been killed by bashing them on rocks and bending them rather than loose pivots. Oh, or clutches wearing out and unsuccessful attempts to repair them.

    Full Member

    Previous NX eagle did 800k before it committed harikiri into the spokes. It always needed TLC
    My current SLX M7100 has done 1600k in the last 12 months and is dandy – i have only needed to tune it once in that time
    South downs XC


    Full Member

    An interesting mix of replies so far, but it seems like most people are getting, or would expect to get more than 700 miles out of a mech.

    I have only been on SRAM 12 speed for about a year on two bikes. So far I can’t see much wear on either. I would a rear mech lasts more than 700 miles though. On my commuting bikes I’d be looking for 10000 miles or more from a rear mech.

    I suspect the 9 speed XT mech on my Pugsley must be well over 5000 miles by now and it’s still working on probably it’s 4th set of jockey wheels.

    If 12 speed wears out that quickly I will be changing back!

Viewing 29 posts - 1 through 29 (of 29 total)

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