Having issues with Bosch CX Motor, wondering is anyone is facing this issue?!

[justin122120]

Hi everyone, hoping to see if anyone has had this issue. I was on a ebike ride climbing up a loose rock firewood when all of a sudden I lost complete motor assist and power. The Bosch motor no makes a very loud winding noise under any mode but gets louder when its on the higher power modes like turbo or emtb. I have no more pedal assist and the motor just makes a loud winding and whirling noise. I can't upload the MP4 file to this thread but if anyone can help me out with that that would be great so I can showcase the video and see if anyone else is having the same problem. My bike is a 2024 Pivot Shuttle AM with the Bosch CX 4 Gen Motor, Wireless Mini Remote, System Controller with LED Lights and On/ Off button

UPDATE: Ran two diagnostic and the motor kept coming up with error code 523001 Drive unit error - sensor system. Motor is currently being sent back to Bosch and mostly likely I'll be sent a new motor in return

FINAL UPDATE: Received my new motor, very pleased with the overall Bosch Warranty! My warranty was started on April 10th 2024 and was finished when I received my motor on April 18th!

 

[arTNC]

Could you clarify which bike and display model you have? I have the simple but effective Purion on a Trek Rail 7, but since you mention downloading something I guess you have some kind of smart system?

 

[justin122120]

Could you clarify which bike and display model you have? I have the simple but effective Purion on a Trek Rail 7, but since you mention downloading something I guess you have some kind of smart system?

Yes I've got a 2024 Pivot Shuttle AM, it came with the Bosch CX Motor 4 Gen, Wireless Mini Remote, Bosch System Controller with just the normal LED lights and On/Off Button

 

[JP-NZ]

. I have no more pedal assist and the motor just makes a loud winding and whirling noise.

Sounds like the motor is done, take it back to the dealer for replacement.

 

[RustyIron]

The motor goes whirry whirry, but the sprocket doesn't go spinny spinny?
It's time visit your Pivot Authorized Repair Center.

 

[Paulquattro]

I can only mirror the above
Sounds like you have a drive gear gone to me from your explanation .
Keep us posted

 

[arTNC]

Being somewhat new to the issues of the CX motor, I know the front chainring nut can loosen. No, I haven't gone out to the shop to inspect my Rail 7 to confirm this, so I thought I would just throw this out. Is it possible for the nut to back off enough to where the chainring is no longer retained on the output shaft? I'd think the chainring would rattle around and grind horribly, and it would be obvious to the owner what the problem was. Otherwise it does sound like an internal drive component issue.

 

[Tribey]

Being somewhat new to the issues of the CX motor, I know the front chainring nut can loosen. No, I haven't gone out to the shop to inspect my Rail 7 to confirm this, so I thought I would just throw this out. Is it possible for the nut to back off enough to where the chainring is no longer retained on the output shaft? I'd think the chainring would rattle around and grind horribly, and it would be obvious to the owner what the problem was. Otherwise it does sound like an internal drive component issue.

The chain ring would be obviously very wobbly if the nut was that lose. Just put a paint spot on the nut and another adjacent on the chain ring for an obvious tell tale of if being lose, but in 4 years it's not been an issue for me.
Back to your dealer I would suggest.

 

[Bearing Man]

Hi everyone, hoping to see if anyone has had this issue. I was on a ebike ride climbing up a loose rock firewood when all of a sudden I lost complete motor assist and power. The Bosch motor no makes a very loud winding noise under any mode but gets louder when its on the higher power modes like turbo or emtb. I have no more pedal assist and the motor just makes a loud winding and whirling noise. I can't upload the MP4 file to this thread but if anyone can help me out with that that would be great so I can showcase the video and see if anyone else is having the same problem. My bike is a 2024 Pivot Shuttle AM with the Bosch CX 4 Gen Motor, Wireless Mini Remote, System Controller with LED Lights and On/ Off button

This could be one of three things on a Gen 4. And what @arTNC said is the most likely. The sprocket lockring nut can back off very slightly, or be tight but not physically clamping the chainring spider hard enough. If the spider is aluminium, it quickly wears the splines off the spider allowing the motor to spin but not the spider and chain. If the spider nut is spinning and the chainring isn't, this is what has happened.
The other two things are internal, and are: the sprag clutch bearing or there are two gears pressed together in the transfer box and these can slip causing loss of drive.

 

[justin122120]

The chain ring would be obviously very wobbly if the nut was that lose. Just put a paint spot on the nut and another adjacent on the chain ring for an obvious tell tale of if being lose, but in 4 years it's not been an issue for me.
Back to your dealer I would suggest.

Chain ring definitely wasn't lose

 

[justin122120]

This could be one of three things on a Gen 4. And what @arTNC said is the most likely. The sprocket lockring nut can back off very slightly, or be tight but not physically clamping the chainring spider hard enough. If the spider is aluminium, it quickly wears the splines off the spider allowing the motor to spin but not the spider and chain. If the spider nut is spinning and the chainring isn't, this is what has happened.
The other two things are internal, and are: the sprag clutch bearing or there are two gears pressed together in the transfer box and these can slip causing loss of drive.

It's definetly not the chain ring spider. I pulled the motor out so it can be sent back to Bosch and the chainring spider was in perfect condition with the split teeth intact. The Lock ring was plenty tight. It sounds like the second thing you described might be the issue since it is an internal issue with the actually motor. I ran a diagnostic report and the motor kept throwing codes for drive unit error and problem with the sensor system. We'll wait to see if Bosch sends a new motor and is they update me on the actual reason for the motor failure