Problem with new XT 11-46 11s cassette

Gear cable routed the wrong way round the mech…? Triple check this! 😜

Nope, everything routed correctly, it’s not like the mech is trying to move the chain it’s more like the chain is too wide for the cogs, which it shouldn’t be as it is an 11s chain and every other gear is fine.

Although you trust the bike shop, follow the Shimano set up instructions yourself to see if you can rectify it.

Checked your mech hanger is straight?

Mech hanger was also replaced and is new

Replaced and new is 100% NOT the same as straight...

If the mech hanger was bent wouldn’t I have issues getting into the 11 tooth cog? Which I don’t. It was bent before being replaced, after an off, which is why everything was replaced, it would not go into the smallest cog when bent. The dropout was a replacement Orange item and my bike is a Clockwork Evo 29.

There is little to no tolerance between the chain and the 13t cog when the chain is on the 15t and before replacing the 13t cog one of it’s teeth was actually fouling the chain when it was settling onto the 15t cog. Every other gear is fine. The 13t cog is the one with its own spacer built into it.

If the mech hanger was bent wouldn’t I have issues getting into the 11 tooth cog?

Depends on how bent and in which direction. Slightly out of true can give full range across the cassette and decent shifting on the whole, but weirdness in part of the cassette. It's the first thing I'd check when people complained of less than perfect shifting.

Whenever I've had problems with one or a couple of gears and everything else is working well it's been the gear hanger that needed a small tweak.
Get the bike on a stand and look at where the chain is catching, Then gently tweak the hanger a very small amount until it doesn't catch.

That’s my point, it shifts fine but when the chain is on 15t cog the 13t cog is somehow fouling it. It isn’t a shifting problem.

Might have to do that and have a good look.

If the mech hanger was bent wouldn’t I have issues getting into the 11 tooth cog?

depends how it's bent or twisted, how the stop screws are adjusted.

What freehub is it too. I've seen some of the more fancy looking (but cheap and nasty) aluminium freehubs that allow the individual sprockets to be mounted clocked.

Hi, just thought I'd chip in with a second hand observation.

My friend just put on a brand new 11speed XT cassette (and chain) on a new build and is experiencing very similar symptoms, when we where out at the weekend one of the outer plates on the chain looked like it had been fouled by the cassette and had splayed out...nearly snapping.

Not sure how much use that is, maybe Shimano had a quality control issue or something..

Sounds exactly like what is happening here, to a lesser extent thankfully. I’m considering getting it swapped. It’s mounted on a Hope Pro4 hub by the way and all the spacers are correctly fitted.

Jst had the same issue sent the first one back and the second was the same ....ordered a sunrace and all was fixed ...

I sent the second one back thinking I was loosing my mind or had lost my touch as a mechanic but when I went to purchase one directly from my lbs to see if it was a stock issue they said they didn't have any stock as they had to return there stock due to a qc

Glad to hear I’m not the only one! Sounds like I need to swap it and hope or get a sunrace?

Replacement cassette just fitted and tested. Exact same issue. Bugger.

silly question, are using an 11 speed chain?

and your chainline is ocrrect, not too inboard?

Yes and yes. Gone from a XT 11-42 cassette with zero issues (replaced as worn with chain), new 11-46 and this annoying problem. The only change is a new dropout hanger after an off but it is aligned. I don’t have a different cassette to swap and compare, was thinking of getting a Sunrace 11-46 to see if the problem persists or disappears, given similar issues reported above with the Shimano.

Quick link on the right way round and connected properly?

You need to work it through systematically. 13T cog is tiny. If it fouls the same point every time on the chain its the chain. If it fouls the same tooth every time then its the cassette.

IMHO, things like bent hangers and badly adjusted gears usually cause continual issues, not at a specific point every rotation.

But you’d be surprised how 1/4 turn or badly adjusted mech endpoints can cause issues only in certain gears.

Me, I’d start from the beginning. Undo cable. Set end points. Tighten cable and adjust up / down shift till it shifts smoothly through all gears and is quiet in all gears.

Then move on to looking at chain/tooth fouling.

If its he same with different cassettes then it does seem to point to set up.

Is the chain the right way round with the writing on the outside and the plain side facing inward towards the wheel

And a new hanger is not the same as using a hanger tool to set it properly

Chain on the right way and all originally fitted and adjusted, including the mech hanger, by a bike mechanic at a well known shop in Hope, Derbyshire. A shop I have used for years without issue.

I’ve had this with a 12 speed SRAM cassette. No matter how hard I tried I could not make the fouling go away. In the end I just found the offending tooth and filed it down a bit.

Three brand new Shimano cassettes tried now, all with the exact same issue. Everything else checked and fitted/adjusted correctly, including mech hanger alignment. Must be a Shimano QC issue, can’t be anything else.

At this point, I think I'd be tempted to try a shim/spacer made out of an old tin can. Might give just enough space to stop the catching, but hopefully not thick enough to make indexing on the smallest cogs impossible. May not work, but it'll not cost anything other than a bit of time. There doesn't seem much point in just throwing another cassette at it.

Have you tried the wheel/cassette on another bike?

Have you checked the quick link is definitely 11 speed, and definitely facing the right way. If yes to both, I'd be changing the quick link anyway to rule it out, they've caused me problems before.

Even if there is a QC issue what are the chances of getting 3 in a row with the exact same issue while not seeing another post on here reporting the same problem?

I agree but if you look through the thread there have been similar issues with other people. Maddison weren’t aware of it but the set up on my bike is sound. New chain, rear mech, cassette, mech hanger and cable, all fitted by 18bikes at Hope and checked twice since then, there is nothing in the setup that is obviously the problem. It’s a head scratcher and comes down to simply not enough space between two sprockets to avoid the chain fouling.

New inner cable. Perhaps the old one is kinked right at that point.

I will look at the quick link but when on the stand it is two teeth on the smaller sprocket which are fouling the chain each revolution.

The inner cable was replaced but worth a try I guess.

I have/had this problem with the same setup on two bikes, one of the teeth on the smallest sprocket catches the chain. I got it down to a combination of a tight clutch and indexing ever so slightly out. With the clutch off I can get it to go way by adding more cable tension using the shifter barrel, with the clutch on it was still there a bit so I backed off clutch tension a bit and seems to have almost gone away.

Even if there is a QC issue what are the chances of getting 3 in a row with the exact same issue

Based on it's a mass-production item, up to 100%?

Based on it’s a mass-production item, up to 100%?

Yes it could be but how many people are reporting the problem? Even if it was one in ten to get three in a row with the same issue would be pretty unlucky

Backing off the clutch tension hasn’t helped in my case. I’m hoping the offending teeth will wear down to a point they no longer catch but not ideal.

sorry for the thread resurrection
@thorpie , did it get better over time ?
I have just fitted a new cassette and chain and it's doing the same as what you got

Hi, it got better over time. Changed to a new one in the spring and the new one does the same thing. That’s 3 or 4 XT cassettes I’ve used over a couple of years and all catch when in the same sprocket.

Thanks