Cassette Wobble: How Much is Too Much?

[Cameron]

OK, I'm finishing up the drivetrain on 26" Specialized Epic Comp. I'm setting it up 1x10 with Shimano SLX shifter, SLX cassette and ZEE derailleur. The wheels are a few year old Deore XT.

Last night I slipped the cassette onto the freehub and tightened the lock ring down to 40nm with a torque wrench. Next I put the wheel on the bike and installed the chain. Verified everything was tight and that the wheel was firmly all the way up in place in the rear dropouts. Next I gave the crank some turns by hand and let the rear freewheel. That's when I noticed what seems to be to be a lot of wobble in the cassette when freewheeling.

My first thought was maybe I didn't actually cinch down the cassette properly or that maybe I did need to include a 1mm spacer behind the cassette since it's a 10 speed cassette going on a 9/10 Shimano freehub. So I took it back apart, made sure there was no debris between the back of the cassette and the hub, etc. Then I restacked the cassette on there (again w/out a 1mm spacer) and verified the height of the "top" of the cassette (littlest cog) was well proud of the top of the freehub to ensure the lock ring had room to tighten all the way down. Plenty of space there so re-tightened the cassette, re-install on the bike and same thing. Still a good amount of wobble when freewheeling.

Next, tried it with the 1mm spacer behind the cassette and still the same thing. Installed a different cassette (Shimano 105) and same thing. Next I pulled the cassette completely and just spun the thing up by hand holding one end on the axle by hand and the other hand holding the freehub body and just watching the freehub to axle relationship. Doing this I can clearly see it's the freehub body wobbling vs. the axle when freewheeling. Freehub body feels tight in the hub and while the hub bearings feel a little like they could use a re-greasing I don't feel any "catch" spots in the rotation that might make me believe the axle is bent.

I didn't take a video of my exact setup on my bike, but did find a video on YouTube showing exactly what I'm seeing on my bike. I converted it to a gif for easier posting here. See below. This is just about exactly the same amount of wobbling I'm seeing on my setup.

https://j.gifs.com/X6nRMl.gif


Is this normal? I've heard many times before "some" wobble is normal but I don't have any benchmark on what would be considered normal vs. excessive. Neither of the other 2 geared bikes I ride right now do this and both are equipped with Shimano cassettes. One is a Chris King hub and the other is a 5800 Shimano hub.

For reference on the bike I'm having this wobble on it's a Deore XT, WH-M775-R hub and an SLX, HG81 cassette.

I was thinking my next step was to pull the axle out of the hub and see if it's actually bent?

[Matthew]

I am in the process of looking for some 26" disc wheels for my MTB. In my searching I have found this to be a complaint for this particular XT wheel, at least to those that have reviewed it on MTBR's website. I unfortunately don't know if this wobble is a big deal though so I can't offer any help there. The good folks here that have lots of wheel building knowledge will likely chime in though and offer great opinions. Somebody like oldpotatoe. Matt

[Mark McM]

Is it normal? Well, it's not unusual. Shimano's freehubs are notorious for having wobble. And wobble is amplified by the sprocket size, so the bigger the sprocket, the bigger the lateral excursions.

Generally the wobble will be accommodated by the flex in the chain (Shimano's chains are quite flexible) and the lateral travel built into the derailleur top pulley, so you will likely not experience any problems. Just make sure the derailleur limit travel is adjusted well to prevent the chain from fall off toward the spokes.

[AngryScientist]

i have a 105 level hub that has at least that much wobble. never had a problem over multiple thousands of miles. those were my gravel wheels for a long while and saw lots of rough road miles.

[Cameron]

In my searching I have found this to be a complaint for this particular XT wheel, at least to those that have reviewed it on MTBR's website.

Is it normal? Well, it's not unusual.

i have a 105 level hub that has at least that much wobble. never had a problem over multiple thousands of miles.

Crazy. My internet searching has told me a lot of the same about there's just some wobble in them and not to worry about it. I mean, I am not worried about it failing in some catastrophic way, just seems.... wrong to see that much movement there. Not really confidence inspiring.

I think I still may pull the axle out and see if it rolls straight or if I can find any signs of not-straightness. Then reassemble and just finish setup and see how it shifts when out riding ¯\_(ツ)_/¯

Thanks for the input dudes.

[11.4]

Try it with chain tension on the cassette. Then the wobble pretty much disappears.

[ColonelJLloyd]

try it with chain tension on the cassette. Then the wobble pretty much disappears.

+1

[TEMPLE]

I have Ultegra wheels and the rear wheel cassette easily wobbles that much. Maybe more. The bike shop said no problem and they were right: I put about 2000k on those wheels and the shifting was always problem free and crisp.

I can't say the same pleasant things about the wheels overall, which frequently came out of true and, just at the end of the summer, a spoke broke. I weigh a lot (215ish) so that may have been a factor, but I was pretty careful about what kinds of roads I went on with these wheels, so it surprised me. The hub also sounded scratchy right from day 1, so I wasn't really happy with these wheels. They are easy to service, so points for that, but they cost too much to need that kind of TLC so early in their life.

None of my other wheels (Mavic, Giant and DT Swiss) have any wobble (or broken spokes/problems with trueness). Just saying.

[CampyorBust]

It’s a 26er! Ride it in to the ground!

[CampyorBust]

oops double post. er delete delete

[FlashUNC]

Not a new thing. Pretty common to Shimano and I've seen some that are even worse work just fine.

You're in the clear.

[bikinchris]

Another reason to not like Shimano.

[cmg]

is that the result of the plastic bushing in the free hub?

[Cicli]

is that the result of the plastic bushing in the free hub?

I think that only Mavic

[ColonelJLloyd]

Another reason to not like Shimano.

Yawn. What's he gonna do replace it with Campy MTB kit?

[Tandem Rider]

It’s a 26er! Ride it in to the ground!

We ought to be riding everything into the ground. :)

Then get new :eek:

[oldpotatoe]

Crazy. My internet searching has told me a lot of the same about there's just some wobble in them and not to worry about it. I mean, I am not worried about it failing in some catastrophic way, just seems.... wrong to see that much movement there. Not really confidence inspiring.

I think I still may pull the axle out and see if it rolls straight or if I can find any signs of not-straightness. Then reassemble and just finish setup and see how it shifts when out riding ¯\_(ツ)_/¯

Thanks for the input dudes.

Ayup, very common on shimano hubs of that level and vintage. Probably not an issue and a new FH body may not solve it completely or much. It'll probably 'work' just fine. Not an axle, it isn't turning with the wheel/cogset. A FH body 'issue'..they just aren't made to very high tolerances, and also a real old design..like a 30 year old design.

[lonoeightysix]

if you really feel frisky, there is a method to cracking open the free hub and playing with spacers/washers to reduce the amount of play. it's sort of a pain, requires at least one specific shimano tool (TL-FH40, or homemade equivalent), a big-boy hex wrench, and a new free hub dustcap.

The resulting improvement will be negligible.

[Fatty]

I had a 105 hub with a bit of a wobble. Never a problem with shifting. Just bugged me a bit when the bike was in the work stand.