Bosch cx gen 2 motor making vibrating screeching noise

Gnomes

Finding my (electric) wheels
Jan 11, 2019
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I've had my Haibike SDURO HARDSEVEN for 6 years now till recently theotor has started to make a vibrating slipping screech for a second or two when under load then it's ok and but as soon as I slow down /stop at junctions etc and pull away with force I get this horrendous noise .
There is no play in the cracks but there is some mild sound from the bearings (nothing like the issue sound) when I rotate the cranks forward so that suggest some bearing wear but I'm sure it's not this that causing the noise
 

soundwave

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May 23, 2015
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only ebike motor center services these but there are nylon gears inside the motor and mine was pretty worn when i sent my motor in to get it serviced like others on here.

other wise its a new motor as bosch wont sell the bearings to service them
 
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soundwave

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soundwave

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May 23, 2015
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stop riding it contact ebike motor centre he is a bosch dealer and a m8 you just need to remove the motor from the bike put it in a box and they will pick it up and give you a quote to fix it.

i upgraded my 2014 performance motor to cx.

tho he will sell you the stuff to service it but you will need a shop press.

he did do one guys motor and it still kept slipping like that so id not ride it at all
 
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Gnomes

Finding my (electric) wheels
Jan 11, 2019
15
1
stop riding it contact ebike motor centre he is a bosch dealer and a m8 you just need to remove the motor from the bike put it in a box and they will pick it up and give you a quote to fix it.

i upgraded my 2014 performance motor to cx.

tho he will sell you the stuff to service it but you will need a shop press
I'm definitely not capable of repairing it myself but I have a Bosch service centre in Southsea where I live so may show them the video .
If I go the postal route is the motor easy to disassemble from the frame and what about the wires inside
 

soundwave

Esteemed Pedelecer
May 23, 2015
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no point they will just send it to him and charge there fee and his for it all you need to do is remove the motor its just 3 bolts that holds it on under the cover 1 power cable 1 for the display and 1 for speed sensor.

its 315 quid to fully service it https://www.ebikemotorcentre.com/repair-overhaul-service/

ebike shops cant fix jack like this they charge 50 quid to plug it in and just replace parts no fixing anything because it is a throw away item like a iphone
 
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soundwave

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May 23, 2015
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no he gave him one to use while he sorted it ;)
 
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saneagle

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I'm not knowledgeable on motors or how they run but the in my video doesn't sound like it's a bearings issue . It sounds like something slipping under load
It's not bearing noise. It sounds like a commutation issue to me. Have you been riding in the rain or into water just before it started?
 
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soundwave

Esteemed Pedelecer
May 23, 2015
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its the clutch behind the torq sensor imo as other guy replaced hub and wheels and still did it but peter sorted it ;)
 
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AndyBike

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Nov 8, 2020
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Certainly sounds like something slipping to me as well. In fact its the kind of sound you get off a car when the clutch is fubar.

TBH after 6 years maybe time for a replacement.
As far as im aware its about 500/600 for new motors, but if you consider a repair is 300, its not too big a jump.

It's just a shame that all motors seem to have their own bolt mounting patterns, and theres no (to my knowledge) universal mounting bracket/adaptor.
 
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Gnomes

Finding my (electric) wheels
Jan 11, 2019
15
1
It's not bearing noise. It sounds like a commutation issue to me. Have you been riding in the rain or into water just before it started?
I use the bike daily for work so yes it gets wet in the rain but it's not been in any rain for over a month now so I would say not associated with water penetration
 

saneagle

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Oct 10, 2010
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The mode of failure goes something like this: Thr crank seal wears and let's in a bit of water. The water gets into the bearing and damages it. The excessive play in the bearing damages the seal further and let's more water into the motor. From there the water can get into the electronics or the vital mechanical parts.

Whatever the damage is, the cause is the same and the only solution is to open the motor, replace the crank bearing and its seal, and inspect everything else. The damaged parts should be obvious. Some motors are full of water. The only thing you have to decide is who's going to do the repair. Either way, you need to take the motor out of the frame. One thing you can't do is continue using it because it'll only get worse and more difficult to repair. There are a few good YouTube videos on how to take the motor out and open it up.
 
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Gnomes

Finding my (electric) wheels
Jan 11, 2019
15
1
The mode of failure goes something like this: Thr crank seal wears and let's in a bit of water. The water gets into the bearing and damages it. The excessive play in the bearing damages the seal further and let's more water into the motor. From there the water can get into the electronics or the vital mechanical parts.

Whatever the damage is, the cause is the same and the only solution is to open the motor, replace the crank bearing and its seal, and inspect everything else. The damaged parts should be obvious. Some motors are full of water. The only thing you have to decide is who's going to do the repair. Either way, you need to take the motor out of the frame. One thing you can't do is continue using it because it'll only get worse and more difficult to repair. There are a few good YouTube videos on how to take the motor out and open it up.
Thankyou for your helpful reply. I've decided I will send it off to the ebikemotorcentre who get very high recommendations on here