Q&A: Why do Shimano SLX, XT, XTR (Micro Spline) hubs CREAK and FAIL?

Shimano SLX (M7110), XT (M8110), and XTR (M9110) rear hubs of Micro Spline family were introduced in 2019. The plan was to introduce them as SCYLENCE hubs, however Shimano dropped this idea in the last moment. Despite the advantage of 12 speed Micro Spline design, these hubs have been causing lots of issues from the early miles. Starting with some creaking and then following with complete failures. Let's sum up all the experience on this. And a bit of history as well.

My other videos on these freehubs:

MTBR forum thread with numerous complaints on this problem:

Cyclingtips news on Shimano Scylence from 2019:

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Contents:
0:00 - Intro
0:45 - History
2:10 - Creaking
3:05 - Crashing
3:50 - XTR spacers
4:30 - Warranty
5:11 - Positive cases?
5:43 - Show must go on
6:12 - Conclusion

Credits (appearance order):

#cycling #shimano #service

[wattyler]

I'm currently working on a new build and I was looking at these hubs for my wheel set
I'm glad I watched your video first. My previous build is fitted with the previous xt hubs and they've been absolutely fine.

[kgws]

Thank you! My 2022 Shimano slx freehub that came on my Specialized Turbo Levo Comp mtb failed at around 2, 000 miles. I purchased the bike in Nov 2021 and at the time it had all Shimano components. It just started grinding and ate the metal gears. I had it replaced. Luckily I had bought a spare free hub when the bike was new, as during Covid it was impossible to find one. Specialized switched to Shram in January 2022 for their components. Now I know why.

[herbgoergen]

Thanks for this explanation! My new Giant MTB came with SLX components and started creaking within weeks of purchase, I had to take it back to the shop several times before they finally relented and replaced the hub. After another six months, it's started again and I notice the bike is 'ghost pedalling' when you push it forward, deja-vous all over again. From your experience it sounds as if the only true solution is to replace the hub with something other than Shimano.

[FrancisDonovan]

thanks for sharing the part number on the black spacer. My spacer on my XT hub failed today (white spacer). I'm in the United States and shimano USA has no stock available. I ordered a couple of them from the EU and paid a lot for shipping. Still much cheaper than a new hub. This is the hub's last chance. Next step is a rebuild with a DT Swiss 350.

[alexandreschulter]

I have the Shimano M8120 wheelset. I only ride trails and the creak started at about 40 hours. Replaced the yellow spacer with black one, and put special grease on it. After 20 hours it's creaking again. The bike is still in warranty, but I don't have time to waste. I'm buying the 410 ou 510 hub and try to relace with the same spokes. Plan B is DT Swiss 370, which is VERY expensive in my country.

[nappsuelze]

My recently bought XT rear wheel lastet 80km without creaking, took it apart yesterday and found the black spacer you mention.
After regreasing it's quiet again. Hope it lasts for the coming season without to much maintenance, over the next winter I'll consider switching to another Hub.

[_S_]

FWIW, im at 7000km on a slx hub, and its doing just fine. Riding on a Rocky Mountain Altitude powerplay, which until recently with the launch of the new DJI motor was the most powerful EMTB motor out there. So the hub has to endure quite a bit. I did grease and oil the hub from the start because it was noisy (i figured shimano forgot to grease it or whatever...), but not with any special shimano kind of grease. I just used SRAM butter on outer teeth, and basic sewing machine oil on the inner teeth. It has been working flawlessly for me so far. Just yesterday i had to regrease it because over time it does start to make a bit more sound. But after regreasing / oiling its completely silent again. And i have to say, i like it very much for that reason. I would never go back to a noisy freehub again. After these 7000km the teeth all look like new and the plastic spacer shows no wear (it did came with the black one, not white).

[Justcyclestuff]

Just went out for a ride tonight, and sure enough this has now happened to me bits of plastic everywhere inside my hub, an hour of pulling it apart and putting back together, so annoying think I’ll be replacing hubs with Indy9 hydra

[JEllesgaard]

My XT hub came with the white spacer. It crumbled and locked up freehub. Got the black spacer on warranty. Same problem but lasted longer. Have been running 1, 5 year without the spacer now. But today the aluminum axle broke on a big jump. So when I got home I replaced it with the steel axle from an slx spare hub.

[shaunbeakley]

I had the deore group set of the same version (that they discontinued because it was somehow even worse than the SLX ones) and I didn't know that it was broken so I rode it until it literally destroyed the entire hub. Took like 4 years though

[timewind]

I have a same problem with mine hub. But ots making noise only when pedaling with some force. Is that the problem?

[DiGiTaLdAzEDM]

Reminds me of a saying I read lately--"newer is always better...even if it isn't...", or that's what they would like us to believe. I have two wheelsets with XTR 965 hubs. Never an issue with them...rock solid. From 2003-4-not sure.

[JoeVan]

I have put about 2, 000 mi on the most recent XTR hubs. Still going fine. A lot of that downhill and enduro. I have yet to have the freehub problem but it seems like by design it will happen eventually. You kind of wonder why Shimano gave this the green light or did not use something more durable like aluminum rather than a plastic spacer. The previous XTR hub, the last HG driver was an absolute tank just like all the other XTR hubs. I noticed when I picked up this new version they did feel lighter but also not quite as durable. I'm happy the bearings are still decent which is something that I blow up routinely on cartridge bearing hubs. I also learned long ago never to use lower tier Shimano hubs. If it does not say XTR or dura Ace, use something else. I guess time will tell how long this set that I have will go

[drazek]

Is it problem only with shimano hubs ? I want to buy Novatec d902sb microspline, I hope it has different construction

[AczeOne]

I have this hub, it's been squeaking like this since yesterday, I'm pissed! because I have to take the bike to the service center now. I have some kind of SLX hub on my old bike, I bought the wheels used, and it's been working since 2018, and here's the new super hyper one and it's gone crazy... 😩

[mattk]

Any update after a year?

My experience so far: I have an XT hub with about 800 kilometers, noise free. I also xtr hub that started creaking in under 200 kilometers.

[srbhit]

Hello, I have the Shimano FH-MT401 Center-Lock Rear Hub 135mm and my question is, is this freehub affected too?

[thebdceigal]

Have play in my shimano FH-MT510 went to a shop he said they are seeing lots of these. Switching to DT Swiss and not buying shimano anymore.

[toddstiers]

I had a complete failure in the free-hub body of my 12sp SLX - lasted 2500+ miles, I went SLX after my XT 12sp failed. Replaced 12sp xt derailler and shifters too way too early too, SRAM 12sp NX is even better

[Hard_Work_Is_Rewarding]

I am a bit confused... Is this a problem with all Microspline hubs (e.g. DT Swiss 350/240 etc) or just the Shimano hubs? Thanks. PS Would be a bit of a problem for the road if the future road cassettes switch to Microspline from HG11...