Ochain S compatibility - Bosch CX Gen4 and Sram Transmission crankset

[dhjunkie]

Dear all

not sure where to post this but just want to share my recent not really nice finding when I have tried to install my new OchainS on Bosch CX Gen4 together with Sram GX Transmission crankset. So you are aware if you would be thinking about such upgrade.

This setup is NOT COMPATIBLE !!!!!

REASON:
The GX Transmission Ebike ISIS Crankset doesn´t have enough clearance and is hitting the Ochain Adjustment ring and can not rotate freely when fully tightened.

The bad thing is that this is nowhere written and even Ochain product page states the opposite: OCHAIN | S

• Ochain can guarantee the compatibility just with SRAM crankset.

Appearently Ochain was/is aware of this and in 2024 they have introduced Ochain Crankset eliminitating this compatibiltiy issue. AS I have found out just now when searchign the mighty internet. However this crankset is not more available and not even presented on the Ochain webpage.

I have messaged Ochain on what is their suggestion on how to deal with this situation. Especially when you pay €400 for something which is supposed to be working with all SRAM cranksets but is not. I am really curious how will they react and what solution they will offer.

BTW. I guess same compatibility issue will be also with Bosch Gen 5 and SRAM crankset with OchainS.

 

[dhjunkie]

Little update from Ochain:

They adviced that the rubber seal on the engine shaft should be removed together with the metal retain clip -
I will try it but have some concersn about the seal removal what impact it will have on the bearings.
Can some tell me whetehr the seal is by default on all Bosch CX Gen4 engines or it depends on the bike manufactruer?

 

[Bear-uk]

Little update from Ochain:

They adviced that the rubber seal on the engine shaft should be removed together with the metal retain clip -
I will try it but have some concersn about the seal removal what impact it will have on the bearings.
Can some tell me whetehr the seal is by default on all Bosch CX Gen4 engines or it depends on the bike manufactruer?

That seal and clip is a service part and it's the only thing that's stopping your motor from filling up with water.
Unless the Ochain has a seal that's supposed to replace the original one, then the last thing you want to do is to remove the seal and leave the motor shaft open to the elements.
Sounds like a crap idea to try and solve a design fault.

 

[dhjunkie]

That seal and clip is a service part and it's the only thing that's stopping your motor from filling up with water.
Unless the Ochain has a seal that's supposed to replace the original one, then the last thing you want to do is to remove the seal and leave the motor shaft open to the elements.
Sounds like a crap idea to try and solve a design fault.

Absolutely agree Bear-UK. No way this is the right suggested solution. will never remove that seal. Ochain is struggling appearently as well. Suggested to replace the OchainS with an OchainE without Adjsutment knob which is interferring.

 

[HollisterRedgrave]

Little update from Ochain:

They adviced that the rubber seal on the engine shaft should be removed together with the metal retain clip -
I will try it but have some concersn about the seal removal what impact it will have on the bearings.
Can some tell me whetehr the seal is by default on all Bosch CX Gen4 engines or it depends on the bike manufactruer?

Compatibility questions like this are always worth checking before investing in new components. It's great that people share their experiences because it can save others a lot of time and money. After reading technical discussions for a while, I sometimes Play Chicken RD Australia to take a quick mental break.

Have you tried it?

Edit: Thanks for the update.

 

[dhjunkie]

Have you tried it?

No and won´t do it. And neither it would fix the issue, as ochain would than hit the frame outer ring anyway.
Like you can see on this picture - red circle.
Seems to be really either an technical manufacturing issue with this particular Ochain or the crankset. As I have messaged a friend who is riding Ochain on Bosch CX Gen5 (technicall same crank interface as Gen4) with Sram Ttype90 crankset and has no compatibility issue.