Bosch Performance Line Noise

Niallzagreb

Finding my (electric) wheels
Mar 24, 2019
13
5
I purchased two new Gazelle bikes for me and my wife. Identical model both with Bosch Performance Line motors.

My bike’s motor sounds like a very noisy milk float - whining away as you pedal.

My wife’s motor is significantly quieter - almost silent.

Can anyone advise why one engine is so much quieter than the other?
 

soundwave

Esteemed Pedelecer
May 23, 2015
16,182
6,319
you will have to take it to the dealer and get them to run the diagnostic software and see if anything shows up.

only other thing you can do is see if there is any play in the cranks that would mean the bearing has failed or failing and crud getting inside.

do any error messages show up?
 

Amoto65

Esteemed Pedelecer
Jul 2, 2017
807
502
61
Cheshire
Just taken my Carrera Crossfuse into Halfords yesterday with a suspected main bearing failure after 7 weeks and 150 miles, will be going back tomorrow to hear the verdict but pretty sure my diagnosis is right. Steve W....
 

Niallzagreb

Finding my (electric) wheels
Mar 24, 2019
13
5
No. Both motors pass the diagnostics test. Dealer says they don’t know what the problem is and can’t return to Bosch as it’s passes all diagnostics. Both motors perform fine. It’s just that whining noise is really annoying especially when out on a run in the country where peace & quiet are appealing
 

Andy-Mat

Esteemed Pedelecer
Oct 26, 2018
2,214
562
77
I purchased two new Gazelle bikes for me and my wife. Identical model both with Bosch Performance Line motors.

My bike’s motor sounds like a very noisy milk float - whining away as you pedal.

My wife’s motor is significantly quieter - almost silent.

Can anyone advise why one engine is so much quieter than the other?
It probably still has guarantee? Then the dealer must fix the noisy one....
regards
Andy
 
  • Like
Reactions: soundwave

Niallzagreb

Finding my (electric) wheels
Mar 24, 2019
13
5
You would have thought so but as long as the diagnostics says it’s good then they say it’s working ok - which it is but just noisy.

Maybe it’s possible that one bike has a more recent version of the performance line?

The difference between the two noise levels has been obvious since day one...
 

soundwave

Esteemed Pedelecer
May 23, 2015
16,182
6,319
problem is if a bearing is going or some other part inside the motor it wont show up in the software but the dealers are not allowed to open the motors if under warranty so the only option is to send it back for replacement under warranty.

if the dealer is saying no errors and wont return it because of this there talking out there ass as ppl on here have had the same problem and had a new motor fitted.
 

soundwave

Esteemed Pedelecer
May 23, 2015
16,182
6,319
each side of the motor has a bearing so if you grab the crank arms try and move it up and down as there should be none at all and be totally stiff.
 

soundwave

Esteemed Pedelecer
May 23, 2015
16,182
6,319
The play in my crank is backwards and forwards when you hold both crank arms.

it is why you need to lube both sides with grease and the bearing cover as to not let any crap get inside the bearings cos when it does it is like grinding paste, my ses wheel bearing sounds like a bag of spanners when it goes ;)
 

soundwave

Esteemed Pedelecer
May 23, 2015
16,182
6,319
Yes - thank you - did that and there is no play at all. Just a noisy motor!
well all you can really do is keep riding it and see if it gets worse or not and then take it from there as you or the dealer cant open the motor casing to see what is up.

tho they do tend to go around the 4-600 mile mark if you have a duff motor.
 

Niallzagreb

Finding my (electric) wheels
Mar 24, 2019
13
5
Just to offer a follow up on the noise issue if anyone is interested....

So I took the bike to the dealer again. They simply said that motors are meant to be noisy. I guessed part of the problem was that I bought the bikes in Rotterdam so my local Bosch ebike dealer is not the shop that sold it to me and to make matters worse is in a different country!

So I contacted Bosch direct through their webpage contact form and got an instant reply which after a few more emails led to Bosch contacting the local dealer and asking them to send the motor to Bosch. Two weeks later they sent a replacement motor.

Now the motor is much quieter!

They did not say what the issue was but I got it sorted! Good to know Bosch are helpful!
 

Niallzagreb

Finding my (electric) wheels
Mar 24, 2019
13
5
And now an immediate follow up....

The motor is beautifully quiet but since I got the bike back last week the chain keeps jumping off the front chain set....

Any ideas what I should adjust.....or do I have to go back to the dealer?
 

MarcusT

Pedelecer
May 5, 2019
83
39
NE Italy
Go back to the dealer. After what they put you through, they need to put the bike in perfect working order
 

D C

Esteemed Pedelecer
Apr 25, 2013
1,140
575
And now an immediate follow up....

The motor is beautifully quiet but since I got the bike back last week the chain keeps jumping off the front chain set....

Any ideas what I should adjust.....or do I have to go back to the dealer?
Did the new motor come with a new front chain wheel?
If it did and the old chain was re-used that could be the cause of the problem.
Dave.