Bosch cx motor bearings after only 570 mile ??

TheBikePilot

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Oct 9, 2018
928
905
Clapham, London
Nah mine was back in 10 days or so. They replaced it with a new one in my case. Does the bike shop have a demo bike they can lend you?
 

TheBikePilot

🎥SHOOTER🎥
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Oct 9, 2018
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Clapham, London
Well, the mechanic on the shop told me it was replaced rather than refurbished. This was over a year ago so the policy may have changed.
 

Akemtb

Member
Mar 1, 2019
44
38
Anchorage Alaska
Dealer is replacing mine, the bearing started making noise at about 2100 miles. After washing and on it's side in truck there was brown rusty water coming out of left crank bearing, never good. The dealer said ride as long as you can, not sure when the new motor will be in. A Bulls Monster E FX, bike is about 15 months old. I have pressure washed a couple of times, will be more careful in the future.
 

Beekeeper

🍯Honey Monster🍯
Aug 6, 2019
1,751
2,197
Surrey hills
That would be a shame :( If you think about it, your normally aspirated bike will probably need a new BB set by spring £20 - £70? But if you keep riding your ebike with plenty of silicone grease around the bearings it will be fine = £0 Or if it fails and under warranty you get a nice new motor = £0 Or if it's out of warranty, it will probably just be a main motor bearing £10 - £15 :D

Why does the main motor bearing wear out faster than the others inside the motor? Is it under more stress because it takes the weight of the rider? What about the non-drive crank bearing, surely that would be taking an equal weight. Why doesn’t that one also wear out at the same rate?
 

Bearing Man

Ebike Motor Centre
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Sep 29, 2018
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UK
Why does the main motor bearing wear out faster than the others inside the motor? Is it under more stress because it takes the weight of the rider? What about the non-drive crank bearing, surely that would be taking an equal weight. Why doesn’t that one also wear out at the same rate?
It has nothing to do with stress or load, it is simply that the main motor bearing is just more exposed than the crank bearings. It’s where all the rubbish falls off the chain and where people like to clean, so it’s chances of survival are limited.
 

Bones

E*POWAH Elite
Subscriber
Apr 3, 2020
894
1,175
Harrogate
The Bosch booklet I got with my new motor in Nov said the motor is dust and splash proof only. Its currently sat collecting dust as there is no one at my dealer to repair it due to covid and Bosch arnt answering the phone or replying to dealer emails it seems. I had to get my old 26" bike out of mothballs and it nearly killed me trying to pedel it.
 

Bearing Man

Ebike Motor Centre
Patreon
Sep 29, 2018
975
2,329
UK
The Bosch booklet I got with my new motor in Nov said the motor is dust and splash proof only. Its currently sat collecting dust as there is no one at my dealer to repair it due to covid and Bosch arnt answering the phone or replying to dealer emails it seems. I had to get my old 26" bike out of mothballs and it nearly killed me trying to pedel it.
If it’s out of warranty, we can fix it if you can get it out the bike?
 

Beekeeper

🍯Honey Monster🍯
Aug 6, 2019
1,751
2,197
Surrey hills
Hi @Bearing Man

I know filling the right hand crankshaft cavity with silicone grease is a good idea but what happens in the future when you want to do this again?

Do you pack new grease on top? I assume you would potentially then be trapping in moisture or debris or do you scoop out the old grease and clean the entire cavity.
How would you go about removing the original old grease as it’s quite a deep cavity?
 

Bearing Man

Ebike Motor Centre
Patreon
Sep 29, 2018
975
2,329
UK
Hi @Bearing Man

I know filling the right hand crankshaft cavity with silicone grease is a good idea but what happens in the future when you want to do this again?

Do you pack new grease on top? I assume you would potentially then be trapping in moisture or debris or do you scoop out the old grease and clean the entire cavity.
How would you go about removing the original old grease as it’s quite a deep cavity?
I use the blunt end of a drill bit and a screwdriver both with a bit of rag draped over them. Once all the grease and dirt is out, forget re-greasing, fit one of our new crank seals and forget about it for life Crankshaft seal for Bosch. Total protection for the right-hand crankshaft bearing. - (y)
 

deksawyer

E*POWAH Master
Jan 11, 2020
387
452
Fife, Scotland
Mine is starting to get a bit "ticky" sounding when I pedal now, with almost 400 miles from new.

I had the motor lock after it sitting for a couple of month over Xmas etc. Managed to free it easily and it still works well, but just a bit noisy. I think it's maybe getting worse, but hard to tell. I remember it ticking when pedalling from new.

I'll keep riding it until the end of lockdown and do a warranty claim, or just keep riding until it dies.

I already fitted the mudstopper and the crankshaft seal (after the lockup to be clear) and I think it was too late.

@Bearing Man - can the crankshaft seal be removed easily in order to re use it?

And more generally, can any local Bosch service centre claim on the warranty? Bike was bought online from the other end of the country....
 

Bearing Man

Ebike Motor Centre
Patreon
Sep 29, 2018
975
2,329
UK
Mine is starting to get a bit "ticky" sounding when I pedal now, with almost 400 miles from new.

I had the motor lock after it sitting for a couple of month over Xmas etc. Managed to free it easily and it still works well, but just a bit noisy. I think it's maybe getting worse, but hard to tell. I remember it ticking when pedalling from new.

I'll keep riding it until the end of lockdown and do a warranty claim, or just keep riding until it dies.

I already fitted the mudstopper and the crankshaft seal (after the lockup to be clear) and I think it was too late.

@Bearing Man - can the crankshaft seal be removed easily in order to re use it?

And more generally, can any local Bosch service centre claim on the warranty? Bike was bought online from the other end of the country....
Crank seal can be re-used but you have to be careful extracting it.
When a bearing has seized it is because the ball bearings inside have rusted to the races because the bearing was wet when stored. The rust damages the ball and race and it is the beginning of the end for that bearing.
If you can actually hear the bearing while riding, it's too late! The bearing is now destroying itself rapidly.
As long as you are the original owner of the bike and have proof of that, warranty should not be an issue.
 

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