Problems with Bosch Bearings??....

PeteT

Just Joined
Jul 14, 2018
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Hi, Sorry to shout straight out as a noob, but I see there are a lot of people on here struggling with the Bosch bearing issues. I am now on my third motor (under warranty). A friend of mine bought his bike second-hand (no warranty) and having bearing issues couldn’t get it sorted because it was the left crank bearing as well as the main motor bearing that had failed.

We found this guy who has a “how to page”, bearings and everything! Took us around 2 hrs to fix and it cost less than a rear cassette....Worth a look: - www.performancelinebearings.com
 
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Fat Rat

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Jun 7, 2018
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Hi welcome
He has been mentioned on here before
And I had also seen the site on the net But another hit is definitely worth mentioning
It’s all about spares as with anything
:)
 
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MikeS

Esteemed Pedelecer
Jun 29, 2018
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I thought I read somewhere in one of the posts that there was a number of tips to prolong the life of the bearing, but I can't find anything on performancebikes website.
Reading his home page it seems the obvious one is to not let water anywhere near it but are there any others.
Also the implication is that in the later Active Line motors Bosch have made some mods that eliminate or remove the problem?
Mike
 

Fat Rat

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Jun 7, 2018
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What amazes me is some people are obviously harder on there bikes than others both in use and in washing them after
I’ve seen people on standard bikes go through bottom bracket bearings like crazy and it’s mainly down to washing and maintenance
This is the key
The bearing guy is saying he has never seen anything but rust being the problem so water ingress is the main issue so in that theory just pack the outer faces with grease as a routine
Especially through the winter months
It’s got to help
Oh and as a side note don’t drowned the motor especially while its hot as all it will do is cool rapidly and draw in water through its weakest points the bearing seals
Happy peddling :)
 

Artstu

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Aug 2, 2009
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What amazes me is some people are obviously harder on there bikes than others both in use and in washing them after
I’ve seen people on standard bikes go through bottom bracket bearings like crazy and it’s mainly down to washing and maintenance
This is the key
The bearing guy is saying he has never seen anything but rust being the problem so water ingress is the main issue so in that theory just pack the outer faces with grease as a routine
Especially through the winter months
It’s got to help
Oh and as a side note don’t drowned the motor especially while its hot as all it will do is cool rapidly and draw in water through its weakest points the bearing seals
Happy peddling :)
Bearings wear out even when there is no water ingress, rider strength and hills climbed have a bearing on the rate of wear too.
 

GLJoe

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May 21, 2017
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Bearings wear out even when there is no water ingress, rider strength and hills climbed have a bearing on the rate of wear too.
Yea, but when you have people saying things like they have worn out three different motors/bearings, each only lasting under a thousand miles, everything points to the user doing something fundamentally wrong and not an inherent problem with the bearing/motor itself.
 
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Fat Rat

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Yea, but when you have people saying things like they have worn out three different motors/bearings, each only lasting under a thousand miles, everything points to the user doing something fundamentally wrong and not an inherent problem with the bearing/motor itself.
100% agree
The bearing are not wearing out there rusting out that’s water ingress
 

the_killjoy

Esteemed Pedelecer
May 26, 2008
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Yea, but when you have people saying things like they have worn out three different motors/bearings, each only lasting under a thousand miles, everything points to the user doing something fundamentally wrong and not an inherent problem with the bearing/motor itself.
To have multiple instances of this happening points to poor design, if it is possible for people to use an ebike in a fundamentally wrong way.
 

Fat Rat

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To have multiple instances of this happening points to poor design, if it is possible for people to use an ebike in a fundamentally wrong way.
We’re talking off road abuse here not popping to the shops
Play hard things break
I ask you this
Through the winter you get loads of people bailing through floods in there cars , nice hot bearings being cooled by water consequently they draw in water as they cool it’s physics
Couple of months later the bearings are buggered
Now is this
The cars fault
The bearings fault
Or the person behind the wheel for going through the flood

I’m not trying to start a war here but did Bosch make the bearings and there associated seals and do they have control over the rider and usage

What I will say thou is Bosch should be offering bearings and spares for after warranty use , you shouldn’t have to rely on a 3rd party to supply bearings
Allthou it’s good they do :)
 

the_killjoy

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May 26, 2008
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I agree Bosch should step up, but irrespective of who makes the bearings and seals it was Bosch who designed the unit and signed them off as fit for the task.
 

Fat Rat

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I agree Bosch should step up, but irrespective of who makes the bearings and seals it was Bosch who designed the unit and signed them off as fit for the task.
I think we have hit an impass on our definition of Fit for use Not fit for abuse

We’re all different so I’m leaving it at that

:)
 

Haibike Rider

Finding my (electric) wheels
Jul 13, 2018
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Hi All, I am "the bearing guy". I would just like to add a few points to this discussion (without promoting anything).
Section 17 of my "how to" guide shows how to extend the life of both the crank and main motor bearings, just for info.
As for the Bosch design, I have to agree, it was a little short sighted not to put a water seal in front of the bearing, but I can see they were kind of caught between a rock and a hard place. It would require three seals to achieve a water tight motor. The left and right crank bearings would require sealing, along with the main drive spline. This would cause a curtain amount of extra drag, leading to extra battery consumption.
Some of us would probably be happy to put up with that but many would not. As stated on my site, there are complex sealing bearings that would be a better choice but again, what are the consequences to find out?
I had to buy 1,000 bearings, and opted for same spec because to find out that drag is an issue would be too painful for me.
Nice to meet you guys.
 
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Artstu

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I had to buy 1,000 bearings, and opted for same spec because to find out that drag is an issue would be too painful for me.
Nice to meet you guys.
I remember NBR bearings wanting me to order 1000 too when I was replacing my Bosch classic bearings, that one has soldiered on for another 5,000 miles or so. Pleased you had some made and I'll get one soon, ready for when I replace the motors 3rd drive-side bearing.
 
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MikeS

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Jun 29, 2018
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Hi All, I am "the bearing guy". I would just like to add a few points to this discussion (without promoting anything).
Section 17 of my "how to" guide shows how to extend the life of both the crank and main motor bearings, just for info.
As for the Bosch design, I have to agree, it was a little short sighted not to put a water seal in front of the bearing, but I can see they were kind of caught between a rock and a hard place. It would require three seals to achieve a water tight motor. The left and right crank bearings would require sealing, along with the main drive spline. This would cause a curtain amount of extra drag, leading to extra battery consumption.
Some of us would probably be happy to put up with that but many would not. As stated on my site, there are complex sealing bearings that would be a better choice but again, what are the consequences to find out?
I had to buy 1,000 bearings, and opted for same spec because to find out that drag is an issue would be too painful for me.
Nice to meet you guys.
Sorry Haibike - I may be missing something. on your page called How to... there is a little bit of text and a link to instructions about how to actually replace the bearings. Section 17 of those instructions mentions greasing them - is that what you mean by advice on how to extend the life?:
"17. It’s up to you but the right-hand crank bearing would be only replacable with specialised equipment and a lot of finger crossing so I tend to pack this bearing with silicone grease on a regular basis to extend its life as far as possible. (I am working on a solution for righthand bearing replacement, bear with me)."
Mike
 

soundwave

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May 23, 2015
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5. Main motor drive gear and clutch bearing assembly.

it is inside that i think so not so easy to smash that one out from inside of that.
 

Haibike Rider

Finding my (electric) wheels
Jul 13, 2018
7
7
59
Sorry Haibike - I may be missing something. on your page called How to... there is a little bit of text and a link to instructions about how to actually replace the bearings. Section 17 of those instructions mentions greasing them - is that what you mean by advice on how to extend the life?:
"17. It’s up to you but the right-hand crank bearing would be only replacable with specialised equipment and a lot of finger crossing so I tend to pack this bearing with silicone grease on a regular basis to extend its life as far as possible. (I am working on a solution for righthand bearing replacement, bear with me)."
Mike
Sorry Mike, I do mention in the home page that water is normally the issue and in the "how to" section, not only what to do to prolong the life of the motor bearing, but also the crank bearings! I am working on a video to cover this in a little more depth (even though I am selling bearings and this is doing me out of repeat business! o_O)
This is a new site, it's not my main business and time/money is a it limited for me. But I would like to expand it to cover some other technical issues people are experiencing through poor design. I have just completed a page on the Haibike SES sprocket issues and this goes into greater depth on prolonging bearing life etc.
I really appreciate your feedback though and will work to improve what I have done so far.
Pete.
 
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Haibike Rider

Finding my (electric) wheels
Jul 13, 2018
7
7
59
5. Main motor drive gear and clutch bearing assembly.

it is inside that i think so not so easy to smash that one out from inside of that.
The right hand crank bearing is behind the clutch bearing assembly. If this one fails, you're in trouble! It would need to be pressed out gently but the big issue is, you can't currently buy a replacement.
I only have my motor to experiment on, so I don't want to remove it for measuring in case I damage the clutch bearing!
Eventually, it would be great to source or make every bearing in the motor. If anyone has a wrecked motor they would like to sell or donate I can then go a lot further.
 
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