Chain jumping off cube reaction.

[Gilbo]

Hi
Anyone out there experienced the chain getting sucked up between chainring and chainstay on a cube reaction hybrid 2022 model. Tried all I can think of
1. Mech aligned
2.new chain
3. Chainring
4. Centralised rear wheel. (It’s on a skewer ,cup and cone bearings)
5. Motor is secure.
Any advice would be welcome.

 

[Eliadn]

I have over 3,5k km on mine, never had such issues. Maybe chain is too long? Worn chainring? Derailleur clutch?

 

[Gilbo]

I have over 3,5k km on mine, never had such issues. Maybe chain is too long? Worn chainring? Derailleur clutch?

Chain,cassette and chainring all been replaced. Mech clutch all serviced and operating as it should. The only thing I’ve not tried is another new chain ,a shimano 1. The owner of the bike is a friend and when he bought all the parts he was supplied a kmc chain and not a shimano 1.

 

[Eliadn]

Perhaps it is too aggressive riding and chain slapping around? The reaction doesn't have a chain guard.

 

[Gilbo]

You could be right the guy who owns the bike does not hang about.

 

[Mikerb]

Another few things you could check.
Firstly, does the chain suck occur in any particular gear/position on the cassette? If it only occurs when on the smaller ( higher) gears it suggests the chain is too long, the derailleur clutch too weak, the jockey wheels partially seized, or the B gap is wrong.
Secondly, you could check the chainline. In general the chainline should look straight when on the middle cog of the cassette. If not, it suggests the replacement chainring has the wrong offset.
Lastly, is the chain, chainring and cassette kept clean and lubed. A new chain is often covered in a wax used to ensure it can be stored in its packaging for extended periods. It is far too tacky to use however and should be stripped and lubed before use.

chain suck at the top of the chainring is usually caused by the chain being in poor condition or having insufficient tension. Chain suck at the botttom ( release) of the chainring is usually because the chain ring is worn or the chain damaged.

ps.....one tip
when charging downhill on rough terain keep the bike in a middle of the cassette gear rather than the highest gears.........that prevents excessive chainslap.

 

[TommyC]

Had a similar problem on my stereo when I first bought it. Cube said it was the chainline and provided a new e13 chainring with 1mm spacer. I’d already put a hope chainring on which was fine. Now have a Pilo one which is thick as hell with chunkier teeth than both the e13 and hope. No problems at all now.

I noticed this only happened in the highest 2 gears though

 

[Gilbo]

Another few things you could check.
Firstly, does the chain suck occur in any particular gear/position on the cassette? If it only occurs when on the smaller ( higher) gears it suggests the chain is too long, the derailleur clutch too weak, the jockey wheels partially seized, or the B gap is wrong.
Secondly, you could check the chainline. In general the chainline should look straight when on the middle cog of the cassette. If not, it suggests the replacement chainring has the wrong offset.
Lastly, is the chain, chainring and cassette kept clean and lubed. A new chain is often covered in a wax used to ensure it can be stored in its packaging for extended periods. It is far too tacky to use however and should be stripped and lubed before use.

chain suck at the top of the chainring is usually caused by the chain being in poor condition or having insufficient tension. Chain suck at the botttom ( release) of the chainring is usually because the chain ring is worn or the chain damaged.

ps.....one tip
when charging downhill on rough terain keep the bike in a middle of the cassette gear rather than the highest gears.........that prevents excessive chainslap.

Cheers bud

 

[Dubreak]

Hi,
I was constantly getting chain suck and Chain off behind the front sprocket on my Cube Stereo 160 2020, Bosch CX Gen 2 Shimano XT drivetrain.
I took the advice of a member up here and put on a SRAM X-Sync Narrow Wide front sprocket and it has fixed it. No more chain offs.
The SRAM sprocket is not meant to be used with the HG Chain I have, and there is a slightly noticeable sound of the chain meshing onto the X-Sync sprocket, but it's not at all loud or annoying. Compared to constant chain offs on rough terrain, it's worthwhile trade off.
I tried chain guides, home made and bought, and also even went so far as 3D printing a sloped spacer to guide the chain back onto the sprocket. Nothing worked until I started using the SRAM X-Sync sprocket.

Regards,