Bosch ebike motor reliability

Dario Troiano

Finding my (electric) wheels
Aug 6, 2016
12
0
65
Bedford
Hi Guys, new here and first post.

Ive read all of the threads about premature bearing failure on the Bosch CX DU and can report that it also happens to full suspension bikes as well.

Ive had my Cube stereo since November of 2016 and have to say i've enjoyed it throughly as I've got dodgy knees and this helps me greatly. currently the bike has covered some 1200km and last week i took it out and and rode muddy trails, almost up to the DU crank centre line.

over the last short while i've been getting a little paranoid with the sound the DU is making. leastwise I'm becoming more aware of the noice the drive makes. from new i could hardly hear anything, but now.....

Anyway, cleaning it as i do every time i get back, i take the chain of the drive ring and turn the crank, its definitely noisy and on rotation has sticky point around the 360 deg of rotation.

So checking out the forum and I see this whole debate on CX DU bearing failures. contacting my local Cube dealer in Bedford, they are more than happy for me to take it in to have a look.

first thing he asks is "do i pressure wash the bike" err yeah! of corse i do, when it gets back from a ride its caked! "do you direct high pressure spray at the crank"?" "hang on say I, i didn't know that i wasn't supposed too"

so he starts on some story about washing the grease out of the bearing and all i can say is where are the warnings about this? if its imperative not to do something to the DU then it needs to be indelibly marked in the area of the bike that should not get pressure washed.

right now, they have inspected the DU and have reported back that the bearings are noisy and there is some telltale rusting on the side of the DU casing.

I've checked all of the paperwork from where it was purchased from and there are no advice notes that advise against washing it with a pressure lance.

they will contact Bosch and ask for a returns carton to be sent out, then we'll see what Bosch's response will be. Happy to take them on as if I'm not riding my bike I've got nothing better to do.

answering another posters comments about hard tail vs full suspension, looks like it make no difference to the outcome.

IMG_4001.JPG

dario
 

Trevormonty

Esteemed Pedelecer
Jul 18, 2016
1,135
564
17
NZ
Don't use high pressure holes on bikes especially FS MTBs, destroys suspension bearings as well as motor's.

I only used low pressure ie hose on shower setting and never degreased chain on bike. Still failed after 2000km.

With replacement motor (assume bosch will sort it), on regular basis make sure you replace regrease extra seal that will be fitted to it. See earlier post for seal kit and grease, will need chain ring lock nut remover. You will need this anyway to replace chainrings with each chain.

No service intervals given, its up to you. With wet winter riding I'll do it ever few rides.

My bike shop never mentioned new seal kit on replacement motor, so it useless if owner doesn't service it. I suspect Bosch never told them about new seal.
 

Dario Troiano

Finding my (electric) wheels
Aug 6, 2016
12
0
65
Bedford
Thanks for the reply. Knowing what i now know...... i've identified all that i need to maintain it properly and the bit about the pressure washer makes sense, as i don't want the DU going wrong again.

i did find a website in italy which is very well priced for the tools and grease etc. I wait with baited breath for what Bosch do / say
 

Doomanic

Pedelecer
Dec 7, 2017
214
61
uk
My bike shop never mentioned new seal kit on replacement motor, so it useless if owner doesn't service it. I suspect Bosch never told them about new seal.
I can't understand why Bosch aren't making sure this info gets out to the current owners.
 

Dario Troiano

Finding my (electric) wheels
Aug 6, 2016
12
0
65
Bedford
I can't understand why Bosch aren't making sure this info gets out to the current owners.
I couldn't agree more! all suppliers could be contacted and bike shops keep records, don't they? it would save us the Ar*e ache and them the money!
 

soundwave

Esteemed Pedelecer
May 23, 2015
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Dario Troiano

Finding my (electric) wheels
Aug 6, 2016
12
0
65
Bedford

soundwave

Esteemed Pedelecer
May 23, 2015
15,973
6,292
i clean mine re lube and put it back you only need to replace it if it has broken as it is just a plastic cover for the bearing.
 

Dario Troiano

Finding my (electric) wheels
Aug 6, 2016
12
0
65
Bedford
i clean mine re lube and put it back you only need to replace it if it has broken as it is just a plastic cover for the bearing.
the most infuriating part of this, is that if there were warning on the bike, then i'd have done what was required of me.!
 

soundwave

Esteemed Pedelecer
May 23, 2015
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my bikes rrp was 5500 and i still had to strip it all down and rebuild it as no lock tight no grease and bolts falling of left right and centre.

was like a toys r us build ;)
 

Dario Troiano

Finding my (electric) wheels
Aug 6, 2016
12
0
65
Bedford
my bikes rrp was 5500 and i still had to strip it all down and rebuild it as no lock tight no grease and bolts falling of left right and centre.

was like a toys r us build ;)
Mine was £2850 and apart from this motor issue its been an angel..... except for the punctures. I suppose a 106 kg bloke and a heavy e-bike all conspire to make punctures an every day event.

hopefully going tubeless will make my life easier from now on LOL
 

soundwave

Esteemed Pedelecer
May 23, 2015
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but did they grease the axle ;)
 

Dario Troiano

Finding my (electric) wheels
Aug 6, 2016
12
0
65
Bedford

soundwave

Esteemed Pedelecer
May 23, 2015
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DSC_0657.JPG
you can put it on the shaft but remove the wheel and also put some on the bearings in the hole as it will all squirt out if loads on the axle.

and check the brake rotor bolts that lock tight has been used ;)
 

Dario Troiano

Finding my (electric) wheels
Aug 6, 2016
12
0
65
Bedford
View attachment 23075
you can put it on the shaft but remove the wheel and also put some on the bearings in the hole as it will all squirt out if loads on the axle.

and check the brake rotor bolts that lock tight has been used ;)
when i get my Cube back ill do that. any recommendation on the type/ grade of grease?
 

soundwave

Esteemed Pedelecer
May 23, 2015
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Dario Troiano

Finding my (electric) wheels
Aug 6, 2016
12
0
65
Bedford
Last edited:

Trevormonty

Esteemed Pedelecer
Jul 18, 2016
1,135
564
17
NZ
I've found bike.discount and bike24 both good for bosch and cube parts. Bike24 have full range of suspension bearing kits, finding right cube PN is a problem. Get yourself spare hanger while at it.
 

Simon C

Pedelecer
Jul 21, 2016
130
93
North West
Reading with interest and have now ordered the bearing seal kit and spider tool as have had the bike Scott Espark for about 13 months. and have just had to have the headset replaced due to water ingress. very poor quality semi exposed bearings in the original head set. Anyway have had no noise from the DU so hopefully with regular maintenance of the bearing seal this will prolong the life. However how would you stand and cost if the bearing failed out of warranty? As it is just a bearing replacement would this require a new engine from Bosch at around £600 or would the bearing be replaceable?
 

Ballynoes

Esteemed Pedelecer
Jul 13, 2017
257
146
Perthshire Scotland
If it's out of warranty.... do what you like... I'm sure I have the skills to replace a bearing on the motor myself, I have seen on a few other posts a supplier for the exact bearings.

When my bike exceeds it's warranty anything goes as far as I am concerned, I sure won't be paying £600 for a new motor if I can get new bearings, for a few quid.... no matter how hard they are to fit.

Getting the parts is usually the hardest bit.... it's out of warranty... it's mine.. I do what I want :D
 
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