Bosch CX Gen4 noisy

[Keisari66]

So far I have pedaled a bit over 1000km on my Mondraker Crafty. The last couple of rides I have noticed the motor noise has randomly and temporarily gotten a lot louder than what I am used to hearing. Anyone else noticed such happening? The rides have been muddy and the motor covers have been coated with thick mud so that could be the reason but I doubt it.

 

[IMeasureStuff]

The motors a fully sealed and a thick coat of mud might actually dampen the noise (but I'm just guessing). I have read the motors can increase in noise after 600km. I'm sure others will chime in who know more.

 

[Keisari66]

Bumped into this and it’s exactly how mine intermittently sounds;


So if I understood correctly Bosch have used aluminum bearings instead of ceramic ones in some units to save weight and it’s apparently been a bad idea.

 

[IMeasureStuff]

Bumped into this and it’s exactly how mine intermittently sounds;


So if I understood correctly Bosch have used aluminum bearings instead of ceramic ones in some units to save weight and it’s apparently been a bad idea.

Wow what a difference. He should have handed the phone over to the other rider to get a better comparison of sound. I had no idea what they were saying. Are there any forum posts that describe the issue with the bearings?
If I was you I would be making a warranty claim if that was the case. I read somewhere Bosch just swap out motors deemed to be faulty in the first 2 years, but in this current environment I would assume there are not going to be much stock available. Even if they can't replace/repair it straight away you could still use it until stock has been sorted out. The key thing would be to make the claim before 2 years of ownership.

 

[Keisari66]

Wow what a difference. He should have handed the phone over to the other rider to get a better comparison of sound. I had no idea what they were saying. Are there any forum posts that describe the issue with the bearings?
If I was you I would be making a warranty claim if that was the case. I read somewhere Bosch just swap out motors deemed to be faulty in the first 2 years, but in this current environment I would assume there are not going to be much stock available. Even if they can't replace/repair it straight away you could still use it until stock has been sorted out. The key thing would be to make the claim before 2 years of ownership.

Yeah I already made a warranty claim this morning. I think I will attach my GoPro somewhere in the frame to record the change in the motor sound for the LBS as it’s not there 100% of the time yet. But it sounds like a broken or soon to be breaking electric motor ?

 

[GrahamPaul]

Bumped into this and it’s exactly how mine intermittently sounds;


So if I understood correctly Bosch have used aluminum bearings instead of ceramic ones in some units to save weight and it’s apparently been a bad idea.

My Gen 4 motor sounded exactly like the second (louder) one until I had the software upgrade. It now sounds like the quiet one.

The change in noise was why I asked the dealer if he had downgraded the motor by mistake!

I wonder whether these two bikes were running the same software version...

 

[Keisari66]

My Gen 4 motor sounded exactly like the second (louder) one until I had the software upgrade. It now sounds like the quiet one.

The change in noise was why I asked the dealer if he had downgraded the motor by mistake!

I wonder whether these two bikes were running the same software version...

I have the newest update. And to my knowledge that orange bikes motor was changed to a new one and it’s silent.

 

[Keisari66]

Took a short video where it doesn’t sound the worst it has sounded. There was next to no workload for the motor and the trail was flat. It was much quieter before I hit the 1000km, I barely noticed it on the pavement when I was going easy. Now it seems to be even louder when going easy than when hammering it ?‍

 

[Keisari66]

My motor is going in for a warranty repair.

 

[GrahamPaul]

My motor is going in for a warranty repair.

Please report back on the fault - hopefully Bosch will tell you what it is.

 

[Keisari66]

They didn’t tell. Bike was few weeks at the dealer and now with a fresh motor.