Clattering coming from new CX2020 motor

WildGuy

Member
Mar 12, 2020
65
98
Cyprus
Especially if judgement is based on youtube sound clips. One really should have a go on one of these bikes IRL before making any judgement.

Personally I have no problems what so ever in terms of noise.

Though not for everyone so simple to obtain a bike to test on proper trail conditions, so many thanks to everyone for posting those videos because, call me cynic, but maybe some dealers could have forgot to mention the issue! I don't possess the so-called "bat ears", but I know that I'm someone who struggles to "tune out" annoying noises of all kinds, so it's enough for me to decide. In fact even for standard operational motor noise I'm very keen for that to be the minimum possible. My understanding, unless anyone disagrees, is that for the main "full power" motors the standard Levo is the quietest. But holding off on any purchase in the current climate so hoping the rumoured Shimano motor people are anticipating will turn out to be the quietest of all.
 

Pylie1

New Member
Jan 19, 2020
38
20
Australia
Especially if judgement is based on youtube sound clips. One really should have a go on one of these bikes IRL before making any judgement.

Personally I have no problems what so ever in terms of noise.
With none available to ride, that's the only thing I have to go by. This opens another question actually. Manufacturers are trying to sell bikes by reviews only. At least they could do is supply a range of bikes, within the country, for people to test ride. Maybe they just don't deserve the sales?
 

dochabanero

Well-known member
Sep 8, 2019
193
187
Sweden
Especially if judgement is based on youtube sound clips. One really should have a go on one of these bikes IRL before making any judgement.

Personally I have no problems what so ever in terms of noise.
With none available to ride, that's the only thing I have to go by. This opens another question actually. Manufacturers are trying to sell bikes by reviews only. At least they could do is supply a range of bikes, within the country, for people to test ride. Maybe they just don't deserve the sales?

Isn’t that the whole point of direct consumer sales vs local bike shops?

If you want to save a buck, opt for direct consumer sales with the pros and cons of doing so. Otherwise find a LBS and test one of their bikes.

I know some of the direct consumer brands actually have road-shows and try to attend events to give us the opportunity to try their bikes. Asking them to open local sales offices in each market would be very expensive and would most certainly be reflected on the price.

Saying they don’t deserve the sales sounds a bit harsh. We are spending a lot of money here as consumers, maybe we need to put in some effort into our purchase, no?

I don’t have endless possibilities of testing all brands where I live. I’d say no one does.
 

Pylie1

New Member
Jan 19, 2020
38
20
Australia
Isn’t that the whole point of direct consumer sales vs local bike shops?

If you want to save a buck, opt for direct consumer sales with the pros and cons of doing so. Otherwise find a LBS and test one of their bikes.

I know some of the direct consumer brands actually have road-shows and try to attend events to give us the opportunity to try their bikes. Asking them to open local sales offices in each market would be very expensive and would most certainly be reflected on the price.

Saying they don’t deserve the sales sounds a bit harsh. We are spending a lot of money here as consumers, maybe we need to put in some effort into our purchase, no?

I don’t have endless possibilities of testing all brands where I live. I’d say no one does.
Are you saying I should fly overseas to test ride a MTB?? I'm happy to spend the money, don't get me wrong there. There aren't any demo to be ridden... in the country. If they are selling bikes within the country, they should have demo bikes, simple. There's no stress, I'm going to support another manufacturer that actually has demo bikes to ride ?
 

WildGuy

Member
Mar 12, 2020
65
98
Cyprus
Isn’t that the whole point of direct consumer sales vs local bike shops?

If you want to save a buck, opt for direct consumer sales with the pros and cons of doing so. Otherwise find a LBS and test one of their bikes.

I know some of the direct consumer brands actually have road-shows and try to attend events to give us the opportunity to try their bikes. Asking them to open local sales offices in each market would be very expensive and would most certainly be reflected on the price.

Saying they don’t deserve the sales sounds a bit harsh. We are spending a lot of money here as consumers, maybe we need to put in some effort into our purchase, no?

I don’t have endless possibilities of testing all brands where I live. I’d say no one does.

I'd have thought the main point was after sales support rather than that. Also hopefully at LBS you can see, sit on and maybe ride round the car park a bike you're considering, but personally I've never been offered the possibility to take it on trail.
 

zaykay

Member
Dec 3, 2019
93
79
Finland
Motor noise is very similar to chain slap. However in the video above majority of extra noises do not sound similar to me than Bosch motor noise. It typically requires freewheeling on rocks and roots. You could hear that few times on the video but majority of noise is some other kind creaking noise from dry parts etc.
 
Last edited:
Apr 18, 2020
188
85
germany
Videos oft are not doing noises justice.

It is also crucial what kind of trail people ride which is also the reason some people notice it more.

Big continuous roots or braking bumps and trails that just get the backend moving harsh and fast make it really annoying.

It's the same noise the shimano motor produces since its a similar design and it just sounds like chain slap bikes from 2010 used to have.
 

Rob Rides EMTB

Administrator
Staff member
Subscriber
Jan 14, 2018
6,260
13,700
Surrey, UK
From Bosch:


When encountering technical terrain on an eBike or eMTB, a vibration of the chain/chainring can occur. Those vibrations can be transferred to the frame, the drive unit and to the inner gear wheel (inside the drive unit). How much vibration is transferred depends on the type of bike (for example hardtail vs full suspension and aluminum vs carbon). In some cases, when freewheeling a metallic sound can be generated when the inner gear wheel is not under the stress of pedaling.

We have been able to recreate this occurrence with different drive units – both from Bosch and competitors of Bosch. The new Performance Line CX is possibly a little more sensitive and the noise is slightly louder than the noise of the other drive units. The CX has a high power density, 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. But performance, efficiency, heat removal and heat-resistance are more important to us.

Usually this noise is drowned out by the sounds of the bike on the trail when descending. Knowing the occurrence, it is easy to reproduce the noise, but the noise does not have any influence on the performance, functionality or reliability of the motor.”

source: Ridden & Rated: 4 of the Best eMTB Motor Systems for 2020 - Bosch vs Brose vs Shimano vs Fazua - Pinkbike
 

Tooks

Well-known member
Subscriber
Mar 29, 2020
480
576
Lincs UK
Noise from the CX2020 motors on rocky descents is something that the guys from e-MTB mag have commented on, they all do it apparently, but it varies in intensity depending on frame design and materials used etc.

There can’t be many Bosch bikes they haven’t ridden.
 

Paul Mac

E*POWAH Elite World Champion
Patreon
Subscriber
Jul 9, 2018
997
1,046
Uk
I have this motor in my Trek Rail which has a carbon frame.
I admit that I would rather the motor didn't make this noise at all, but when it does I don't notice it most of the time, because when your riding terrain rough enough to evoke the noise your normally focused on controlling the bike.
I would describe myself as quite fussy and normally hate creaks and noises on bikes.
 
Apr 18, 2020
188
85
germany
That's the problem for me. When I'm in a section of the trail where this noise occurs I have to be concentrated because of the speed and the consequence of a crash. And a rattling noisy bike just takes away my focus.
 

kntr

Active member
Sep 19, 2019
198
282
USA
When I emailed them a month ago they told me it would go away. I think they are just grabbing at anything right now.

Dear Bosch,
You motor clatters and makes more noise than other motors... just admit it. Tell us you are working on it and move on. Fix it. Don't tell us other motors make noise too. Don't tell us it will go away. Don't tell us your motor doesn't make noise. People have posted your emails to customers and they are nothing but excuses. Fix the noise. Your motor is awesome, reliable, but makes noise.
 

Errol1098

Active member
Jul 8, 2018
65
251
Sydney Australia
I'm not sure if mine clatters or not as I don't know anyone with a different motor and have no reference point. I know I can hear motor noise but it doesn't worry or detract from how much fun I'm having so I don't give it a second thought until I read this thread?
 

Rusty

E*POWAH BOSS
Jul 17, 2019
1,513
1,673
New Zealand
I think there are various reasons for some bikes being louder than others - alloy vs carbon frame, cable routing, chain guide type and shape of chainstays etc. I am still on the injured list so only really cruising around trying to keep some sort of fitness, however on my last 2 rides I was with a guy on a Levo and another on a Merida with the e8000. On a rock garden section I did notice a little noise, but nothing that bothered me - in fact some headset creaking was more annoying. Chris, the Levo guy did not notice anything when riding the same section but John the Merida guy did - saying he noticed something but it was not as loud as on his bike. When I rode his bike I did notice appreciable chain slap through that section.
Talking to a guy with a Trek Rail he said that he had a lot of noise when he first got the bike but during the first service they pulled the motor and sorted some cable routing issues which took away a slapping sound he was hearing.
 
Apr 18, 2020
188
85
germany
I didn't ride the new Bosch but from what I can hear on the videos the sound is similar to the one the shimano makes. It's just annoying if you see other bike who became really silent I the last years and I just can't wrap my head around the fact that the designers didn't think about this when developing a motor for an emtb.
 

Sofaboy73

Member
May 26, 2020
69
35
UK
you do notice it on rough rocky descents (of which we have plenty in the peak district) but on my trek rail it sounds no worse (in fact i'd say less) than any chain slap. as other have said, on those type of descents you're normally focused on line choice an not dying, so although peripherally aware of it, it doesn't bother you. I find the sound of the motor when riding along more off putting, although i'm new to e-bikes so sure i'll get used to it
 

ossiehere

Member
May 30, 2020
20
10
East Sussex
Gen4 bosch on Whyte RS150 not releasing for freewheeling, staying gear all the time. Did start with the noise and slowly got worse. Now when descending its throwing the chain off. Done nearly done thousand miles on it but now getting problems every month with it. Dealer getting a call tomorrow.
 
Apr 18, 2020
188
85
germany
Brose doesn't rattle as far as I know but they are really unreliable. I wouldn't buy until the new motor iterations have a few trouble free miles on them. The rattling of the shimano starts only on really rough stuff compared to the bosch but a new motor is coming from them. I don't know about rattling from Panasonic or Yamaha.
 

Jay__W

New Member
Sep 6, 2020
1
0
Santa Cruz, CA
When I emailed them a month ago they told me it would go away. I think they are just grabbing at anything right now.

Dear Bosch,
You motor clatters and makes more noise than other motors... just admit it. Tell us you are working on it and move on. Fix it. Don't tell us other motors make noise too. Don't tell us it will go away. Don't tell us your motor doesn't make noise. People have posted your emails to customers and they are nothing but excuses. Fix the noise. Your motor is awesome, reliable, but makes noise.
I have a Orbea WILD FS with the clattering problem. I also have a Focus JAM2 which is silent going downhill over any terrain. I have been going thru this thread trying to see if Bosch has taken an official position on this, or if it's even fixable?
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,568
5,060
Weymouth
No doubt frame material and frame design can have an impact on how much the noise is amplified but I wonder if the design of the rear triangle also has an input and is the reason why some bikes are quieter than others. My wife has the 2020 motor in a Cube Access which is a hardtail and it makes not rattling noise at all. For the same reason it could be that a rear shock set differently in terms of compression or progression ( most probably just beyond the sag point or at the midstroke) may also determine whether suspension movement agitates the chainwheel via the chain.
 

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