bosch gen 4 rattle, reply from bosch

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Gavin b

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hi

Put less than 200 miles on my team cube stereo and it seems to have the rattle everyone is talking about, which has got louder over time, to a point where I don't even want to ride it sounds broke.

So I fired a few emails to Bosch
this is what they said.

The clacking and rattling noise is known and has no impact on performance, functionality and reliability.

Here is an official statement from Bosch regarding this noise:
"When riding an eBike/eMTB on rough and technical terrain downhill, vibrations of the chain/chainring often occur. Those vibrations can be transferred to the frame, the drive unit and to the inner gear wheel (inside the drive unit). In some cases when freewheeling, a metallic sound can be generated when the inner gear wheel is not under load. How much vibration and sound is transferred depends on the type of bike (for example hardtail vs full suspension and aluminum vs carbon).

The current Performance Line CX is designed with high power density and thermal stability as well as a highly efficient gearing mechanism and incredibly smooth-running gears. Paired with reduced weight, lower wall thickness and improved heat release it is easier for mechanical noises to be omitted. Therefore the noise may sound a little more prominent when compared with other drives. This noise does not have any influence on the performance, functionality or reliability of the motor. Usually an eMTB also makes several other noises as it navigates these technical sections of trail (tyres gripping/skidding, chain slapping etc) and thus any noises from the motor are drowned out.

On further request: We would also like to note that we continuously develop our products. This includes looking at whether this specific noise can be reduced in the current Performance Line CX."


Best Regards

Your Bosch eBike-team​
 
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Call the bike shop you purchase from and ask them to sort it or give you a full refund.
Was the rattle there from the start, or developed over time? My Trek Rail gen 4 motor is quite with no rattles but about 100 miles on the clock.
 
pgtips said:
Call the bike shop you purchase from and ask them to sort it or give you a full refund.
Was the rattle there from the start, or developed over time? My Trek Rail gen 4 motor is quite with no rattles but about 100 miles on the clock.
Click to expand...

Its in the shop now
Hopefully sorting a new motor under warranty.
Rattle was there from day one, so hoping a new motor will sort it.
 
Gavin b said:
hi

Put less than 200 miles on my team cube stereo and it seems to have the rattle everyone is talking about, which has got louder over time, to a point where I don't even want to ride it sounds broke.

So I fired a few emails to Bosch
this is what they said.

The clacking and rattling noise is known and has no impact on performance, functionality and reliability.​
​
Here is an official statement from Bosch regarding this noise:​
"When riding an eBike/eMTB on rough and technical terrain downhill, vibrations of the chain/chainring often occur. Those vibrations can be transferred to the frame, the drive unit and to the inner gear wheel (inside the drive unit). In some cases when freewheeling, a metallic sound can be generated when the inner gear wheel is not under load. How much vibration and sound is transferred depends on the type of bike (for example hardtail vs full suspension and aluminum vs carbon).​
​
The current Performance Line CX is designed with high power density and thermal stability as well as a highly efficient gearing mechanism and incredibly smooth-running gears. Paired with reduced weight, lower wall thickness and improved heat release it is easier for mechanical noises to be omitted. Therefore the noise may sound a little more prominent when compared with other drives. This noise does not have any influence on the performance, functionality or reliability of the motor. Usually an eMTB also makes several other noises as it navigates these technical sections of trail (tyres gripping/skidding, chain slapping etc) and thus any noises from the motor are drowned out.​
​
On further request: We would also like to note that we continuously develop our products. This includes looking at whether this specific noise can be reduced in the current Performance Line CX."​
​
​
Best Regards​
​
Your Bosch eBike-team​
Click to expand...
It's not really the drive gears, it's the freewheel ratchet. Had they made it very slightly courser, it probably wouldn't do it. (the bit in my photo below)
IMG_6036 (2).JPG
 
Bearing Man said:
It's not really the drive gears, it's the freewheel ratchet. Had they made it very slightly courser, it probably wouldn't do it. (the bit in my photo below)View attachment 29393
Click to expand...

Thanks for that.
Let's hope they do something about it, some are louder than others and mine is a loud one. Apart from that the bike is silent
 
I emailed them and they said it goes away after a few hundred miles.
 
pgtips said:
Yea at list you can get 7-8 motors changes in it's warranty period :ROFLMAO::ROFLMAO:
Click to expand...
Oh it’s much better than that... just junk the motor before 2 years is up and get another under warranty. The warranty period for the new motor resets, so under warranty for a further 2 years. Rinse and repeat for new warranted motors for the life of the bike.

I’m on my 3rd motor in near on 3 years and some 18,0000km

So yeah, my original statement still stands ?
 
Bearing Man said:
Out of the frying pan, into the fire :unsure:
Click to expand...
Well yeah they got a rocket up their as re warranties so I guess so. Much better than still trying to get the pan hot with back and fro bull chit responses.

?Bosh motors are ment to be noisey, if you want quietness you brought the wrong bike ?‍♂️
 
outerlimits said:
?Bosh motors are ment to be noisey, if you want quietness you brought the wrong bike ?‍♂️
Click to expand...

I had a 2019 Levo and now the Trek Rail with the gen4 motor. There is no difference in noise levels apart from the rattle some experiencing with the gen4 motor. I hope I'm one of the lucky ones as so far I have no rattles at all after 100 + miles.

Both great motors, but having my bike in the shop swapping motors all the time is not something I find to be fun.
 
pgtips said:
I had a 2019 Levo and now the Trek Rail with the gen4 motor. There is no difference in noise levels apart from the rattle some experiencing with the gen4 motor. I hope I'm one of the lucky ones as so far I have no rattles at all after 100 + miles.

Both great motors, but having my bike in the shop swapping motors all the time is not something I find to be fun.
Click to expand...
Cool story ?‍♂️
 
I cancelled my Orbea Wild order. The rattle sounded terrible and Bosch and Orbea lying about the rattle turned me off.
 
Hello! I have a Trek Rail 5 2020 with Gen4 Bosch motor and it is very loud when not pedaling and riding on rough terrain but also tried a Orbea Wild FS and produced no sound at all. Does anyone had a replacement under warranty for this problem? It seems that bosch is not making themselves responsible for this uncomfortable sound.
 
outerlimits said:
Oh it’s much better than that... just junk the motor before 2 years is up and get another under warranty. The warranty period for the new motor resets, so under warranty for a further 2 years. Rinse and repeat for new warranted motors for the life of the bike.

I’m on my 3rd motor in near on 3 years and some 18,0000km

So yeah, my original statement still stands ?
Click to expand...
Unfortunately here in Italy it's not possible. Warranty covers failure and replacement until expiration, 2 years. Warranty does not reset, because the obligation is for 2 years no more. Therefore if you junk the motor the last day, next time you have to pay for the replacement. An only then 2 years warranty for the motor starts,because you paid for it. In other words, the warranty for the motors lasts 2 years every time you buy a new motor, or the bike in the first place.
 
I don't hear mine any more. Have done 1300 km. Either I have got used to it, or it has gone away.
 
I thought I’d see what Bosch said and this was their response:-


With regards to the 2020 CX motor noise, we consider this product to be our new Performance Line CX to be the most powerful drive system from Bosch.

It is optimised for sporty, powerful and dynamic riding on the trail. Along with all the positive features that make for a whole new trail experience, it is also quite audible. This is a small penalty for significantly better performance and more riding enjoyment.

Please note, among other factors, noises are acoustic vibrations generated by friction and forces. Efficient power transmission on the eBike is simply impossible without acoustic vibrations.

We would ask you to do at least 300Km on the bike to help it "retract". If you feel excessive noise persists then we would ask you to take the bike to a dealer for analysis and comparison.

We hope this helps

Best regards

Your Bosch eBike team
 
Mines noisy on my rail 7 now the bloody chainring has come loose after 800 miles not impressed with this new gen 4 motor at all
 
Just a thought.

Given the new Bosch gen 4 motor completely disengages at the speed limiter to allow resistance free peddling, is this “clunk” when going from freewheeling to pedalling the motor re-engaging?
 
When you free wheel at any speed over bumps there is a metal rattling sound that comes from the motor and there is still some resistance over the speed cut off as well, when pedalling the motor is nice and smooth and quiet it's only when you are free wheeling there is the noise, the chain ring locking nut also loosens in the same direction as when your pedalling I had to cut a ride short and limp home yesterday as the chainring came loose!!!! I tightened it back up with hammer and screwdriver as I don't have the tool you need going out today to see it loosens again waiting on some locktite to be delivered to see if that works I think Bosch will be getting loads of complaints about this motor I know it's new etc but there are loads of people complaining about the same thing there is a video on YouTube with someone test riding the rail 7 you can definitely hear the sound on there, is it just me or is a lot of the videos with the gen 4 motor being used have music playing in the background to hide the noise coming from the motor ???
 
PhilBaker said:
I thought I’d see what Bosch said and this was their response:-


With regards to the 2020 CX motor noise, we consider this product to be our new Performance Line CX to be the most powerful drive system from Bosch.

It is optimised for sporty, powerful and dynamic riding on the trail. Along with all the positive features that make for a whole new trail experience, it is also quite audible. This is a small penalty for significantly better performance and more riding enjoyment.

Please note, among other factors, noises are acoustic vibrations generated by friction and forces. Efficient power transmission on the eBike is simply impossible without acoustic vibrations.

We would ask you to do at least 300Km on the bike to help it "retract". If you feel excessive noise persists then we would ask you to take the bike to a dealer for analysis and comparison.

We hope this helps

Best regards

Your Bosch eBike team
Click to expand...
Geez, I think they're getting lessons in bullshit talk from Australia's PM.
 
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if it was a design thing, wouldn't they all do it? Mine doesn't make any rattle noise at all
 
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