Sound coming from the motor at 25km/h. Clutch?

[Kingfisher]

I've been hearing this weird sound from my bike. It's like 2 metal disks sliding against each other. At first I thought a brake disk sliding against pad, but it's too metalic.

I'm now figuring it out it happens around the 25kmh mark, when the motor disengages. So is the clutch? What kind of clutch is in a Bosch Gen 3? Bike has 966km

Does anyone have a blow up drawing of a bosch gen3?

Update: Managed to get my hands on a set of circlip pliers, opened up the motor, and regreased all the cogs and bearings. Noise is gone. Happy.

 

[Snoozeboy]

Mine's been doing that since new. I assumed it was the motor disengaging and I assumed it was normal.

It doesn't bother me, but if it's a problem I'll take it in towards the end of the warranty.

 

[Kingfisher]

I've had 3 other CXs, none of them did that. Weird.

 

[lcarron]

Just a question
Are you sure the Bosch CX is equipped with a clutch?

 

[Kingfisher]

Just a question
Are you sure the Bosch CX is equipped with a clutch?

How else does the motor disengage at 25 km/h? I honestly don’t know, that’s why it would be interesting to find some diagrams.

 

[UrbanCityCowboy]

I was just about to post about this. On my bike I get this grating noise but only when the bike is going 16-18mph. I tried switching the motor off to see if made any difference but even with the motor off it does the same thing. It only started doing that after about 300 miles. Any ideas?

 

[Bearing Man]

I was just about to post about this. On my bike I get this grating noise but only when the bike is going 16-18mph. I tried switching the motor off to see if made any difference but even with the motor off it does the same thing. It only started doing that after about 300 miles. Any ideas?

Firstly, yes, the Bosch Performance Line and Performance Line CX Gen 2 motors have two clutch bearings. One disengages the motor and one is your freewheel clutch. Neither make any noise when they reach 25kph though. Screeching or grinding noises are usually because the crankshaft gear circlip has snapped and the gear is now rubbing one of the other gears or grinding against the case and transfer gear assembly.
Hope this helps and I have circlips if you need some?

 

[Doug Stampfer]

I just borrowed a mates trek LT7 (I tihnk) with a gen 2 motor. I heard a sound like brake discs tinging from below whenever the bike got around 30kph. When I slowed down it stopped. Should I warn him something needs attention or is it normal?

 

[Bearing Man]

I would drop the chain off the front sprocket and give the sprocket itself a wiggle to make sure it's tight (sometimes the nut does not reach the sprocket if somethings been changed, so the nut's tight but the sprocket is just floating around). If this is ok, spin the crank backwards and forwards by hand and see what you can feel and hear. It should be smooth and quiet, without play.

 

[Kwagga]

Firstly, yes, the Bosch Performance Line and Performance Line CX Gen 2 motors have two clutch bearings. One disengages the motor and one is your freewheel clutch. Neither make any noise when they reach 25kph though. Screeching or grinding noises are usually because the crankshaft gear circlip has snapped and the gear is now rubbing one of the other gears or grinding against the case and transfer gear assembly.
Hope this helps and I have circlips if you need some?

Hello Bearing Man, Norway looking for some info about this issue. I too got some metallic noise when my Bosch cx motor disengages / engages, like somthing is loose in there somewhere. My dealer told me not to worry, that it was normal. I`m not sure to trust him about that. I hate that noise.
Is there any photos, campaign or something around this issue I could show him?
I`ll be greatful for all info.

 

[Bearing Man]

This is a very uncommon issue but I think it maybe caused by the small metal drive gear than is in the right hand motor cover. When the motor cuts and you're still pedaling, this part spins without load on it. If the bearing is failing or bad, it will rattle in the housing.
Any noise like this is bad and should definitely be investigated at the very least.

 

[Kwagga]

This is a very uncommon issue but I think it maybe caused by the small metal drive gear than is in the right hand motor cover. When the motor cuts and you're still pedaling, this part spins without load on it. If the bearing is failing or bad, it will rattle in the housing.
Any noise like this is bad and should definitely be investigated at the very least.

Thank you for answer my cry for help
I just been at my dealershop, and I told him to take it serious, and fix it. I had to use my angry-eyes at him , but I think he got it....
I`ll report back to you when I get it back.... Soon I hope ?