Chain not settings on cassette

silles

Member
Mar 5, 2022
48
19
spain
Any idea whats going on here;

12 speed schimano d6100
Bike new,.400 km done

It does shift well. Not related to indezing... Chain is not touching other,

1000014146.jpg
 

juggernaut

Member
Mar 31, 2023
31
21
Australia
Chain is stretched or wrong chain.

Doesn’t even look like the KMC chain is their e-bike rated chain. Which I don’t rate that great anyway - stretched mine in less than 800 klms. Compared the sram gx chain on my other 1800w eMTB which is still perfect after 1200klms.
 
Last edited:

mustclime

Active member
Apr 19, 2023
445
358
New Jerzy
Cassette is toast, same with the chain. Alloy cogs are dumb on e bikes. Think I am wrong, pick up a cheap chain gauge and check it.
I am a big guy(100 kg) and I spend most of my time in eco on my Kenevo, my chain is toast in 500 miles. If you are running full power a lot, you can kill a chain quick. My advice is buy good chains and crap cassettes. Higher end cassettes have 1-4 alloy cogs, alloy cogs suck for e bikes. Good chains have higher end parts and tend to last longer.
 

RustyMTB

E*POWAH Elite World Champion
Jul 22, 2020
2,853
6,894
UK
Doubt either of the above posts are true on a 400km bike. More likely the high limit or B screw is out of adjustment. Shimano 12 speed drive trains can be sensitive to misalignment.
 

mustclime

Active member
Apr 19, 2023
445
358
New Jerzy
The 11th speed cog is completely shark toothed. Where are you getting the 400km number from? An app, a guess. If it’s a guess, I always underestimate my mileage on an e bike. My app claims my bike has over 1800 miles on it, I would never guess that number.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
9,017
9,458
Lincolnshire, UK
The cassette looks fine to me. I see no signs of shark-toothing and minimal burring. I agree with @RustyMTB about the B-screw, that upper jockey wheel looks too far away from the cassette.

Setting up 12-speed from scratch always seems to take me longer than ever it did with 9-10 speed. So it is worth consulting a guide from somewhere like Park Tools to ensure that you have not missed a step, or carried it out incorrectly.

I agree with @mustclime that "good chains have higher end parts and tend to last longer". As chains wear, they start to slide up and down the tooth face (creating the shark-toothing); not just on the cassette but on the front ring. Money spent on a good chain is seldom wasted. Not only do they make the rest of your transmission last longer, they tend not to rust quite so quickly.

I also agree with @juggernaut and @mustclime that you should keep an eye on what is known as chain stretch. It's not really "stretch" as such but as the chain gets longer it's not a bad description. So buy a chain gauge, or better still remove the chain and measure it with a metal tape measure. Stretch the chain over a flat surface and measure 100 links from pin to pin. A new chain will measure exactly 50". A terminal one will measure 50-3/8" (ie 0.75% worn). Because the wear accelerates towards the end, I and many others tend to replace at anything above 0.6%. (50.3"). Measuring to 0.3 on a typical imperial tape measure is tricky, so go for 50-5/16" (0.0625%), which is not only close enough, it's also easy to do.

Do not rivet your chain back together, instead take the opportunity to fit a quick link. Google it!
 

RustyIron

E*POWAH Elite World Champion
Subscriber
Jun 5, 2021
1,842
2,881
La Habra, California
Focus on your symptom: poor shifting. Like the others have suggested, check your B screw. I like to run my jockey wheel closer than you read about in the books. If you set the jockey wheel further away, then expect shifting problems. Check your high and low limits. I run mine a little further out than the YouTubers might recommend. Only after everything else is perfect, then worry about adjusting your cable tension.

Since the bike only has 400 km on it, we can almost certainly eliminate wear as being a problem. Only in the most absurd cases can you visually identify a worn chain or cassette. Get yourself a chain checker. Even if you don't need it today, you'll need it some time soon.

Lastly, since I can't see the rest of your drivetrain, I can't diagnose anything from your picture. But keep in mind that a roller chain does NOT ride in the valley between the teeth on the sprocket. The roller chain rides on the leading edge of each tooth. If the chain is riding in the valley, then things are worn out and it will not run nicely.

One last thought: Check the flexibility of each individual link. If it's binding in any way, it will cause shifting problems.
 

silles

Member
Mar 5, 2022
48
19
spain
Thanks for all the replies

Bit more info. Bike is Giant Trance X E+3

I checked millage in app. But I rode the bike about 10 times. Mostly low assistant mode, I am light.

I used the schimano guide to setup.
Lined up 51t mark on cage, etc.

But it wasnt shifting perfectly, had to make it even closer. As per this article

Chain has light wear <0.5%

Maybe it is the disengaging ramp

Whatever that would be :)

Ill keep digging.
Cheers
 

RustyMTB

E*POWAH Elite World Champion
Jul 22, 2020
2,853
6,894
UK
Put the bike in a stand & rotate the crank very slowly whilst watching the chain between the guide pulley & the cassette. You'll be able to see exactly how it's engaging with the teeth & where it's meshing with the cassette. From there, you'll be able to see work out the adjustments needed.
 

silles

Member
Mar 5, 2022
48
19
spain
Yeah just did that, made a video as well:

Not sure how much u can see 🤔
 

RustyMTB

E*POWAH Elite World Champion
Jul 22, 2020
2,853
6,894
UK
KMC chains aren't directional so it can't be mounted the wrong way round. It looks like it's engaging ok but the chain gap longer than the tooth width. One easy thing you could try is to advance the chain on the cassette one link from where it sits now, see if it sits correctly after that.
 

Astro66

Active member
May 24, 2024
323
579
Sydney Australia
B screw is out of adjustment. Shimano 12 speed drive trains can be sensitive to misalignment.
B screw set too high. Too much gap between cassette and derailleur cog. But you'll always get a little bit of unsettled chain where the chain first contacts the cassette in first gear.

Adjust b screw but don't panic. It's not a problem. I have the same cassette and chain.
 

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