Cassette problem on my AllMtn 6

[DDenis]

I just changed the chain on my Haibike AllMtn 6 after 800 km.
The chain jumps off the cassette when I'm on the smallest sprocket.
Is it normal after so few kilometers?
Is there any other solution than to change the cassette as well?
I ride in the mud a lot but I take care of my chain very regularly.
How many kilometers do you do with your chains and cassettes?
Thank you in advance

 

[Mikerb]

Assuming the derailler is corrected adjusted, yes, you need a new cassette.............or if it was working OK with the previous chain, put the old chain back on and ride until it it gives problems. Then fit your new chain with a new cassette.

 

[Jackware]

Can you adjust the end stop to change the position the derailleur stops at slightly further in?

 

[Sander23]

That depends on the state of your cassette and the chainwear of your old chain.if you have gone to far you probably need a new one.
If not and you ride xt-xtr cassette you can normally buy the smallest sprockets and only replace them

 

[Swissete]

Isn't that too strange? I would assume there's a potential disalignment on anyhthing in your bike.
In my case, I have the Allmtn 8,0 with the flyon motor which is quite hard on the chain. Yesterday reached the 3,100kms mark on the stock chain with no issues. It doesn't even have much wear per my chain checker and it never jumped on me.

 

[DDenis]

Everything is perfectly adjusted and it is indeed the chain that slips from time to time over the teeth of the cassette.

It used to do it on the 2 smaller sprockets but now that I rode 50km, it only does it on the smallest one.

While waiting a little longer It might solve the problem thanks to the chain wear.

This is an SRAM GX cassette.

I already had the problem regularly on my Moustache Trail 6 on which I had mounted a Sunrace MX8 cassette for which we fing some "Sprocket Unit 11-13-15".

SunRace 12-speed Sprocket Unit 11-13-15 acheter | Bike-Discount (bike-discount.de)

It doesn't seem to exist for Sram cassette

Too bad

 

[Mikerb]

It seems I was right in assuming that the chain was slipping on the smallest cog rather than the derailleur end stop not being properly adjusted and allowing the derailleur to return too far.
When you fit a new chain on a used cassette, any wear on that cassette is fully exposed. A new chain will not mesh on worn cassette teeth as well. The reason it occurs for you on the smallest cog is likely because that is a cog you use a lot.
There is one adjustment you can try . The smallest cog provides the least chain wrap on the cassette and a new chain will likely sit a little higher on worn cassette teeth. The amount of chain wrap on the smallest cogs can be marginally increased with some adjustment of the B tension screw. Also make sure the rear mech is well lubed so the clutch is able to do its job.

 

[DDenis]

Thank you for all your advice. I tried everything without success but I was just stupid. I have just discovered that the chain link is asymmetrical on Sram Eagle chains (I had never seen this before). That was the origin of my problem. Could be useful for others...