Chain not sitting correctly on sprocket

[CofkoCof]

Hi all,

New member here .
I just bough a new bike and yesterday was my first ride. I noticed a sound when in my 3th or 4th gear (3rd and 4th largest sprocket) .
Today I tried to determine the noise and it seems to be because the chain does not seem to fit perfectly on sprockets (if inspected, you can see small gap between chain and sprocket, causing a "click" when pedalling).

I checked the usual suspects, like high and low limit screws and also B-tension, but that seems to be OK and in other gears I can barely hear the noise.

The chain is Shimano cn m7100 SLX (12-speed), cassete is also from Shimano (Shimano Deore XT M810012 10-51 12s), Rear Derailleur Shimano Deore XT M8100 SGS.

What should I check next? It is entirely possible that I am mistaken and this is not a problem, so here is a picture of cassette and chain. If you take a closer look, there is a gap. Could this really be the problem?

Thanks

[Sagan97]

Hi! Is it a brand new bike or second hand? Sprockets sure look worn out to me. If you look at those three teeth at the very top, they're sooo uneven

[CofkoCof]

Hi,

It's a brand new bike - only did 40km with this bike.
Sprockets might look worn on the picture, but it is just dirt (I haven't thorougly cleaned the whole bike after my ride).

Regarding the teeth I think this is completely by design. This is a 12-speed cassette and I believe all teeth are not identical due to the fact that it is a 1 by 12 cassette. Some teeth are shaped differently to prevent to chain to fall off...but I might be mistaken.
Someone here definitely knows the answer - hopefully they will reply

[Sagan97]

Ah, that's my bad! I didn't think about cassette model, attached image took all the focus. It's definitely a design feature.

[Zviedrs]

Hey,
12 speed chains and setups are very tight. That's based also on personal experience and working on my 29er, it took a while to adjust 1x12 to personal liking. My guess, the chain has not 'set in' or 'worn in' yet. It might not sound very helpful, but I'd simply suggest you to do some more riding and then observe if teeth/chain wears out a bit.

In terms of compatibility, M7100 and M8100 is a legit fit and I see nothing wrong there.

[CofkoCof]

Hey,

Thanks for your response. Yeah, I was also thinking that some more rides could be helpful, because like I said it's a brand new bike.
Hopefully that's the issue

Thanks

[Zviedrs]

It certainly can be the issue. Send updates

[G_M]

I agree with Zviedrs - chain might not be worn in yet. Give it some more miles and then lets see if it helps or not. Another potential cause can be a faulty chain, it can happen. Brand new bike with compatible derailleur-cassette-chain ...

[Painkiller]

To me a new bicycle should have some support from whom ever sold it.

[G_M]

Where did you buy it? Online or local shop?

[CofkoCof]

I bought it online - Canyon.

In the last few days I actually did a few more rides and weirdly there is no more of that "click" sound when pedalling (I guess when chain dropped to sprocket), so for now it seems that this might have been resolved.

It might not have been a problem with the bike, but maybe it's because I am a little bit of a moron .

The rear derailleur (Shimano) has a clutch to prevent chain slap and to keep the chain more tight. Well, I thought that this was supposed to be in "off" and only when doing some more hard downhill stuff that you should enable it. But I read that it should be in "on" position all the time - it is a little bit harder to shift on the lever, but after you get used to it you barely feel it.

So, for someone else that might be reading this - set the clutch to "on"

Not sure if this was the issue or maybe I only needed a little more kilometers.

[Zviedrs]

@CofkoCof how has it been since the mid-February fix? No more clicking?

[CofkoCof]

Hey,

I am happy to say there is no more clicking

Probably it was the combination of multiple things

- chain completely new
- Shimano clutch was OFF and it really makes a difference with chain tension
- about two weeks ago I also slightly modified B-tension

Loving the bike. Just waiting for appropriate times to ride: )

[Zviedrs]

(04-11-2020, 12:52 PM)CofkoCof Wrote:  ,

I am happy to say there is no more clicking

Nice to hear that!
How are you enjoying 1x12 drivetrain? Is this your first 1x front chainring MTB?

[CofkoCof]

Yep, my first 1x12.
I also have slightly older, more cross-country bike and a few weeks ago I went out for a ride with that bike (it has 2x10 drivetrain).

I was amazed how annoying it was for me to operate rear and front derailleur

I very much like it. Less weight, less complexity with setting gears, less clutter on cockpit...also the chain stays on without a chain guard, so that's a big plus.
It's incredible how technology has improved over the last years/decade.

[Zviedrs]

I can imagine Oh yeah. Technology improvements are constant and I am wondering what's next. For instance, Ceramic Speed guys are doing impressive stuff.

Did you make any adjustments with 1x12? I still haven't hit the sweet spot, chain sometimes jumps -2 down instead of -1 and vice versa, but otherwise I can agree with the pros.

[Dom]

Hi

I bought this bike off PinkBike, good condition, bit of a self build as it's a mix of components and I had to replace BB, which was no big issue. However I did notice the chain does not sit properly on the largest cog. It's a bit dirty in the picture as I was just out riding.
Is it chain or Cassette, they both ride well in every other grear so a shame ££ to replace just for the one gear?






Transition Smuggler 2019
KMX chain
Sram GX, 1x12 + custom Chain wheel

[zebracycling]

That clicking noise might be from a slightly misaligned derailleur hanger or a bit of cable stretch. I'd suggest giving the derailleur hanger a quick check with an alignment tool or take it to your local bike shop for a tune-up. Sometimes new cables stretch out a bit after the first few rides, causing minor shifting issues.