"2nd dead bosch gen 4 motor not happy

Gareth

Member
Apr 20, 2024
108
138
Ayrshire
Don't ride in rain or in wet slop.

Umm, if that is the case Kingerz, then manufacturers shouldn’t be selling these things as mountain bikes. And such an approach as you describe isn’t really an option for me.

And no internal combustion engines are not motors

Here’s what the dictionary has to say about ‘motor’ Paul;

Motor (noun)

  • a comparatively small and powerful engine, especially an internal-combustion engine in an automobile, motorboat, or the like.
  • any self-powered vehicle.
  • a person or thing that imparts motion, especially a contrivance, as a steam engine, that receives and modifies energy from some natural source in order to utilize it in driving machinery.
  • Also called electric motor. Electricity. a machine that converts electrical energy into mechanical energy, as an induction motor.


Again I dont agree with the situation and I understand your frustrations and others but as they say you pay your money and take your chances .

Fair enough! Vacuum cleaners do indeed have motors by the way but I don’t think they have ECU’s.:p Anyway enough!:oops: Look that PCB is just the clever little controller inside our ebike motors. It is just seriously frustrating that Bosch won’t support its product – it is a just a part, a part that some of us happen to need occasionally.

And my reply's aren't defending bosch far from it i just see that there not the only company on the fiddle .

I don’t know what it is. But they seem to think they have created a super reliable sealed unit – and in many applications it is probably cutting the mustard, but in some markets as a mountain bike engine it is just not doing the business. But hey it could be kept going with some basic support. Sometimes inside big corporations - well change, or admitting a weakness doesn't come easy.

before you jump ship to shimano... (as a shimano owner) who has been through 2 motors, Shimano motors cant be serviced period...
if you have an error... it is = buy a replacement from shimano... and it is god awful more expensive then 675.. from what Im seeing in this forum... I believe bosch is the better choice still...

Yup I hear they are all crap emin86. I think a certain well known Scottish mtb youtuber go through three Shimano units in a year or so (or thereabouts). Though apparently Brose are both fully supported, plus can be upgraded to become pretty solid useful units. I’d have a Brose, but they only seem to be fitted to Specialized, and I don’t really want one of those – darn it.:mad:
 

rutger

Member
Sep 27, 2021
9
9
NL
I chose a buy new motor cx speed gen 4 for 750EUR from an online dealer
after the local dealers could not give a clear price about the costs and whether or not I would receive compensation from Bosch
When big bike companies say they have never had water in a Bosch engine
and these rare shops will determine what the repair should cost, no thanks..
first the frustration that the engine breaks down after 2.5 years
and now the frustration that I am completely dependent on the dealer's mood..... oh yes...if Bosch is reading along, apparently Bosch cannot make the motor waterproof, but at least make the circuit board waterproof with a much thicker clear coat layer and more space under the circuit board
 

emin86

Member
Apr 30, 2021
23
17
socal
Umm, if that is the case Kingerz, then manufacturers shouldn’t be selling these things as mountain bikes. And such an approach as you describe isn’t really an option for me.



Here’s what the dictionary has to say about ‘motor’ Paul;

Motor (noun)

  • a comparatively small and powerful engine, especially an internal-combustion engine in an automobile, motorboat, or the like.
  • any self-powered vehicle.
  • a person or thing that imparts motion, especially a contrivance, as a steam engine, that receives and modifies energy from some natural source in order to utilize it in driving machinery.
  • Also called electric motor. Electricity. a machine that converts electrical energy into mechanical energy, as an induction motor.




Fair enough! Vacuum cleaners do indeed have motors by the way but I don’t think they have ECU’s.:p Anyway enough!:oops: Look that PCB is just the clever little controller inside our ebike motors. It is just seriously frustrating that Bosch won’t support its product – it is a just a part, a part that some of us happen to need occasionally.



I don’t know what it is. But they seem to think they have created a super reliable sealed unit – and in many applications it is probably cutting the mustard, but in some markets as a mountain bike engine it is just not doing the business. But hey it could be kept going with some basic support. Sometimes inside big corporations - well change, or admitting a weakness doesn't come easy.



Yup I hear they are all crap emin86. I think a certain well known Scottish mtb youtuber go through three Shimano units in a year or so (or thereabouts). Though apparently Brose are both fully supported, plus can be upgraded to become pretty solid useful units. I’d have a Brose, but they only seem to be fitted to Specialized, and I don’t really want one of those – darn it.:mad:
just only replying to my part..
from what I know..

if you want the best warranty and turn around time --> go with the specialized... they may have a higher failure rate.. but their warranty is the best in the buisness hands down AND their turn around time is possibly the best... their motors are rebuildable like the bosch... maybe even have more support? thats something I would ask bearingman or e bike repair motor center.. and regards to the brose motor.. its not only Specialized that uses them...
here are some examples..

- the new rotwild uses them..

- bulls
1719916908827.png

- the new nukeproof mega also uses a sram = rebranded brose motor (should be very interesting)
1719916842557.png


if you want a motor that lasts a long time but is rebuildable... go with the bosch.. as far as the industry goes... the motors with the least failure rates (IMO) is between the shimano and the bosch.. the difference is that when the shimano goes tits up... your buying a new motor PERIOD... bosch has some lee way on this...

unfortunately... until we get the "right to repair" law to be put in place (and I dont think it ever will) since lobbying from corporations is going to win out in the long run, we either have to suck up and put up with it or have a motor company that will stand by their products.
 

emin86

Member
Apr 30, 2021
23
17
socal
I chose a buy new motor cx speed gen 4 for 750EUR from an online dealer
after the local dealers could not give a clear price about the costs and whether or not I would receive compensation from Bosch
When big bike companies say they have never had water in a Bosch engine
and these rare shops will determine what the repair should cost, no thanks..
first the frustration that the engine breaks down after 2.5 years
and now the frustration that I am completely dependent on the dealer's mood..... oh yes...if Bosch is reading along, apparently Bosch cannot make the motor waterproof, but at least make the circuit board waterproof with a much thicker clear coat layer and more space under the circuit board
1719917135416.png

I have a simple solution to this.. .if you are mechanically savy... you can always open up the motor and use dye electric grease on the electrical components.. this is just my hypothesis but it should technically keep moisture and water out from critical electrical components causing them to not short or rust out..

Im wondering if anyone has already tried this???
 

emin86

Member
Apr 30, 2021
23
17
socal
The "smart" system is integrated with the handlebar remote and controller, alarm (if fitted), ABS module and carries the bikes frame number, so the PCB of the motor is also linked to Bosch through their new diagnostics portal. This means you can't just swap a motor or PCB, unless the "new motor" is programmed and assigned by Bosch to that bike.
Sadly, this is the end for us repairing any electrical PCB faults, and a big blow from Bosch against sustainability!!!
would u say that bosch is like shimano in terms of repairability at this point? and if so.. which motor do you recommend?
 

rutger

Member
Sep 27, 2021
9
9
NL
View attachment 143145
I have a simple solution to this.. .if you are mechanically savy... you can always open up the motor and use dye electric grease on the electrical components.. this is just my hypothesis but it should technically keep moisture and water out from critical electrical components causing them to not short or rust out..

Im wondering if anyone has already tried this???

need a better PCB coating that will rule out closure
I also have a photo of my Bosch 2 engine
Here you can see that everything under the clear lacquer remains intact and where no lacquer closure occurs

Schermafbeelding 2024-07-02 152200.png Schermafbeelding 2024-06-15 213904.png
 
Last edited:

Bearing Man

Ebike Motor Centre
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Sep 29, 2018
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UK
would u say that bosch is like shimano in terms of repairability at this point? and if so.. which motor do you recommend?
No. The only reason we can not repair Shimano, is because they will not accept us as a Shimano agent because we are not a bike shop!! Without this, we cannot re-set diagnostics or program the motor with the correct wheel circumference etc. We can repair the Shimano motors, no problem. But we're not prepared to do this if we can't do it properly.
Bosch support us in this regard and we can look after out of warranty Bosch customers. We can still repair any mechanical issue with the new "SMART" system Bosch motors, we just can't swap PCB's or motors, if the PCB fails on a "SMART" system :(.
 

Vaau839

Member
Mar 31, 2020
15
18
Uk
No. The only reason we can not repair Shimano, is because they will not accept us as a Shimano agent because we are not a bike shop!! Without this, we cannot re-set diagnostics or program the motor with the correct wheel circumference etc. We can repair the Shimano motors, no problem. But we're not prepared to do this if we can't do it properly.
Bosch support us in this regard and we can look after out of warranty Bosch customers. We can still repair any mechanical issue with the new "SMART" system Bosch motors, we just can't swap PCB's or motors, if the PCB fails on a "SMART" system :(.
Are Bosch performance line 3rd gen and 4th gen cx comparable in terms of reliability, seals? I've got 30k km on a performance line, would I be able to push cx to similar mileage in the same conditions?
 

Planemo

E*POWAH Elite
Mar 12, 2021
605
706
Essex UK
need a better PCB coating that will rule out closure
I also have a photo of my Bosch 2 engine
Here you can see that everything under the clear lacquer remains intact and where no lacquer closure occurs
Yes it's very simple, Bosch could just make the PCB 'potted' or coat the whole thing with resin like the blue fluid in your pic.

Alternatively, (a radical thought I know) they could avoid having to pot anything and just make sure that any shaft open to the elements is sealed properly just like the gazillions of crankshafts/output shafts etc on engines all over the world.

It's almost like Bosch haven't heard of 4x4 off roaders that manage to plough through sloppy mud up to their windscreens without any engine/gearbox/diff ingress via rotatey, spinny bits.
 

Weeksy

Well-known member
Subscriber
Dec 13, 2019
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No. The only reason we can not repair Shimano, is because they will not accept us as a Shimano agent because we are not a bike shop!! Without this, we cannot re-set diagnostics or program the motor with the correct wheel circumference etc. We can repair the Shimano motors, no problem. But we're not prepared to do this if we can't do it properly.
Bosch support us in this regard and we can look after out of warranty Bosch customers. We can still repair any mechanical issue with the new "SMART" system Bosch motors, we just can't swap PCB's or motors, if the PCB fails on a "SMART" system :(.
I guess the question is. What criteria would they need to accept you as a bike shop, and is it worth it ?
e.g could you partner up with a local shop that's authorised and get it sorted that way ?
 

Bearing Man

Ebike Motor Centre
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Sep 29, 2018
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Are Bosch performance line 3rd gen and 4th gen cx comparable in terms of reliability, seals? I've got 30k km on a performance line, would I be able to push cx to similar mileage in the same conditions?
Bosch never made a 3rd gen CX. The CX lineage went from Gen 2, straight to Gen 4. The Gen 3 only went up to Performance Line without the CX bit. But to answer your question... no seals are interchangeable between generations.
 

Bearing Man

Ebike Motor Centre
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Sep 29, 2018
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I guess the question is. What criteria would they need to accept you as a bike shop, and is it worth it ?
e.g could you partner up with a local shop that's authorised and get it sorted that way ?
Yes, we could get the software without much problem. My argument is that we should be able to do this properly, with the manufacturers (or importers) blessing. This is so we have access to the latest information, updates and guidance.
We want to do this work properly.

Ideally, What we need is everyone who has bought a Shimano powered ebike, but would never buy another because of this repair issue, to write to that bike manufacturer and tell them why they won't be coming back.
I am currently at the Eurobike show this week and will be speaking to as many Shimano powered ebike manufacturers as I possibly can to tell them what is happening to their customers and seeing what the response is!
 

Weeksy

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Dec 13, 2019
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but would never buy another because of this repair issue, to write to that bike manufacturer and tell them why they won't be coming back.
The problem with that is, many of the buyers are happy. Even if replaced under warranty. Until you get more and more who are out of warranty and refused assistance, it'll have to be a waiting game.

For example i can't say "i wouldn't buy another Shimano motor'd bike" yet, because there's no reason for me not to.
 

Vaau839

Member
Mar 31, 2020
15
18
Uk
Bosch never made a 3rd gen CX. The CX lineage went from Gen 2, straight to Gen 4. The Gen 3 only went up to Performance Line without the CX bit. But to answer your question... no seals are interchangeable between generations.
To clarify, I was referring to the NonCX performance line vs CX 4th gen, are they made about the same in terms of waterproofness and reliability?
I've never heard of the performance line failing but plenty of CX failures. Could it be the popularity of that motor, riding conditions or is the performance non-CX build quality superior to CX so there are fewer failures?
 

emin86

Member
Apr 30, 2021
23
17
socal
need a better PCB coating that will rule out closure
I also have a photo of my Bosch 2 engine
Here you can see that everything under the clear lacquer remains intact and where no lacquer closure occurs

View attachment 143148 View attachment 143149
aww so this is a better solution than dye electric grease.... Im not a electrical engineer or anything... but my guess was that since dye electric grease is hydrophobic and non- conductive... it would be great way to protect PCB boards without shorting them out.. since factory solution does not provide a "better PCB coating" I was wondering if this would be an adequate work around...
and also.. may i ask what that clear lacquer and blue substance is?
 
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emin86

Member
Apr 30, 2021
23
17
socal
No. The only reason we can not repair Shimano, is because they will not accept us as a Shimano agent because we are not a bike shop!! Without this, we cannot re-set diagnostics or program the motor with the correct wheel circumference etc. We can repair the Shimano motors, no problem. But we're not prepared to do this if we can't do it properly.
Bosch support us in this regard and we can look after out of warranty Bosch customers. We can still repair any mechanical issue with the new "SMART" system Bosch motors, we just can't swap PCB's or motors, if the PCB fails on a "SMART" system :(.
that is an absolute shame... I hope corporate shimano reads this... not having 3rd parties access to their motors and rendering them un-repairable will make me look elsewhere...
 

Bearing Man

Ebike Motor Centre
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Sep 29, 2018
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The problem with that is, many of the buyers are happy. Even if replaced under warranty. Until you get more and more who are out of warranty and refused assistance, it'll have to be a waiting game.

For example i can't say "i wouldn't buy another Shimano motor'd bike" yet, because there's no reason for me not to.
This is true, and I would not expect anyone still within their warranty period to be unhappy. I am only relaying what I hear on a daily basis from people who are outside of their warranty period and looking at a very large bill for a new motor on an ageing bike, when other makes can be repaired for a quarter of the price.
 

Bearing Man

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Sep 29, 2018
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To clarify, I was referring to the NonCX performance line vs CX 4th gen, are they made about the same in terms of waterproofness and reliability?
I've never heard of the performance line failing but plenty of CX failures. Could it be the popularity of that motor, riding conditions or is the performance non-CX build quality superior to CX so there are fewer failures?
The "non CX Performance Line" was discontinued in 2018, but was made very different from the Gen 4 CX. There are not so many "non CX" Performance Lines around these days so you will hear less about them, but they failed all the same. There is no difference in build quality. When "nonCX" turned into CX it was only a software change, then the Gen 2 CX was discontinued in 2020 in favour of the new Gen 4 Performance Line CX. This is a completely redesigned motor, but has similar failure rates, just different failures.
 
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TheSnowShark

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Sep 7, 2023
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All I know is that Bosch and Shimano will not be among my next choices, since the latter are not in an eco-responsible logic by producing irreparable motors.. this is totally contrary to the ecological idea of the electric bike (like the same for automobile)

Many competitors have just shown new motors which seem very efficient, they will have to take inspiration from the failures of Bosh and Shimano concerning the reconditioning of motors, and if they do so, they will reap very large market shares

🍻
 

Vaau839

Member
Mar 31, 2020
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The "non CX Performance Line" was discontinued in 2018, but was made very different from the Gen 4 CX. There are not so many "non CX" Performance Lines around these days so you will hear less about them, but they failed all the same. There is no difference in build quality. When "nonCX" turned into CX it was only a software change, then the Gen 2 CX was discontinued in 2020 in favour of the new Gen 4 Performance Line CX. This is a completely redesigned motor, but has similar failure rates, just different failures.
Are you talking about this performance line in the picture or was there another one? I have the non smart one in a 2020 Cube emtb and they're still in the cheapest cube reaction performance 2024.

Screenshot 2024-07-03 221931.png
 

Bearing Man

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Are you talking about this performance line in the picture or was there another one? I have the non smart one in a 2020 Cube emtb and they're still in the cheapest cube reaction performance 2024.

View attachment 143229
OK, so this is the Performance Line Gen 3 and is made very different to the Performance Line CX Gen 4. The Gen 3 was primarily designed as a road bike motor, and does not have the strength, power or sealing that you would find on the Gen 4. The low power of the Gen 3 meant great battery range though.

All EMTB's used the Gen 2 CX until 2020 when they all went over to the Gen 4 CX. One manufacturer that I know of in 2020 put them in their "gravel" bikes and this was Cube. Since then, others have tried this too, even putting the Gen 3 in their low end mountain bikes because of the cost saving to the manufacturer. Sadly, the Gen 3's don't do well in water at all. And the reason you don't hear about it, is because 99% of these motors are fitted in road bikes which don't tend to fail like the offroad bikes.

This being said, the Gen 3 Performance Line is the strongest of the gen 3's and ha a large steel drive gear instead of the plastic one fitted to the Active Line and Active Line Plus. This allows the Performance Line to take bigger pedal strikes and hits better. And, if you stick to the gravel, it will do the job.
 

Vaau839

Member
Mar 31, 2020
15
18
Uk
OK, so this is the Performance Line Gen 3 and is made very different to the Performance Line CX Gen 4. The Gen 3 was primarily designed as a road bike motor, and does not have the strength, power or sealing that you would find on the Gen 4. The low power of the Gen 3 meant great battery range though.

All EMTB's used the Gen 2 CX until 2020 when they all went over to the Gen 4 CX. One manufacturer that I know of in 2020 put them in their "gravel" bikes and this was Cube. Since then, others have tried this too, even putting the Gen 3 in their low end mountain bikes because of the cost saving to the manufacturer. Sadly, the Gen 3's don't do well in water at all. And the reason you don't hear about it, is because 99% of these motors are fitted in road bikes which don't tend to fail like the offroad bikes.

This being said, the Gen 3 Performance Line is the strongest of the gen 3's and ha a large steel drive gear instead of the plastic one fitted to the Active Line and Active Line Plus. This allows the Performance Line to take bigger pedal strikes and hits better. And, if you stick to the gravel, it will do the job.
Nice, I've done 30,000 km, with some heavy days in rain too, this should mean that 4th gen Cx should hold up well for similar conditions.

When you mentioned that you can't change motors with a "smart" system, does that mean you can't reprogram a refurbished motor to work on an out of warranty bike? What do the owners do if PCB fails? Do you think there's any hope for software lock to change or be broken in the future to support a refurb motor?
 

Bearing Man

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Nice, I've done 30,000 km, with some heavy days in rain too, this should mean that 4th gen Cx should hold up well for similar conditions.

When you mentioned that you can't change motors with a "smart" system, does that mean you can't reprogram a refurbished motor to work on an out of warranty bike? What do the owners do if PCB fails? Do you think there's any hope for software lock to change or be broken in the future to support a refurb motor?
No this means that if we can't repair a motor for what ever reason, we can no longer offer a remanufactured, service exchange motor and program it to suit your bike. This means that if we can't fix your "Smart" motor, for what ever reason, you will have no option but to buy a new one.
There is no solution for removing the software lock, because the key is held with Bosch.
 
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Slymobi

E*POWAH Master
Mar 13, 2021
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This is the problem when I leave the company for a few days to go to Eurobike show and everything stops! :rolleyes: I will get someone to contact you tomorrow Rusty (y)
So as you're at Euro bike, no doubt you will have seen first hand that there is a fix to all the problems......

Yep Bosch have discovered duck/gaffer tape this is an industrial solution to many a problem

If anyone is unclear.... You may have to be there or maybe watch a few recent videos of Euro bike Bosch related bikes to understand ( the joke ).



P.s cheers @Bearing Man peter for the recent overhaul on my yammy mate, seems to be running sweet again
 

Bndit

Active member
Jul 14, 2022
302
343
Finland
So update to my motor replacement, gonna pick up my bike today. 350€ for motor and 89€ for the replacement. I don`t think it`s bad at all. Of course it could have been little faster operation 😀. I asked to replace also my sifter cable while the engine was away.
Ps. Related ro Bosch, I changed chainring to my wifes commuter, around 10000km ridden in four years and through horrible finnish winters, Her CX4 looked like new under the chainring, even that chaingring certainly didn`t 😀 I but grease under the new chainring to protect the bearings but I`m not sure if it was good idea because everything looked so good 😂

IMG_1264.png
 

Ou812

Well-known member
Jun 26, 2022
768
525
Inverness
@Bearing Man did you have a chance to look at the new Bosch motor at EuroBike? I’ve seen a few videos and it’s already on a lot of new bikes. The next bike I was looking at is Bosch powered (Crestline), wondering if I should wait on the gen 5 motor before buying anything Bosch powered.
 

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