Bosch motor - problems???

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Drago

Legendary Member
Surfing the ebike forums before buying my Trek and Bosch motor issues were far and away the most common, despite not being the most common brand by a fair margin.

I never had a problem, but it was an eye opener. The one people biatch about the most is Suntour HESC or HESC+, and despite being numerically far more common receives a fraction of the reported issues that Bosch do. Mind you, ive had no problems with my Suntour equipped bike either.
 
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chriswoody

Legendary Member
Location
Northern Germany
This video was on youtube yesterday where the bike ultimately needed a new Bosch motor at 750 pounds because the PCB had failed. The cause of the fault with this bike seemed to be the collapse of the bearing which then let in water that led to the PCB failing. If the bearing had been replaced in time then this could have been avoided.



It's an interesting video where the bike shop owner is questioning whether the bike shouldn't have been scrapped. Ultimately though it comes down to companies like Bosch not offering replacement parts and paying no heed to right to repair along with owners needing to pay greater heed to keeping up with maintenance.

Edit: Mmm seems that the video won't play through cyclechat, it's posted from Mapdec Cycle Works in Kendal. Whilst I don't have an E-Bike and probably never will I still found it interesting to watch.
 

UphillSlowly

Making my way slowly uphill
Read this in the paper.
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https://www.theguardian.com/lifeand...-by-failing-motors?CMP=Share_AndroidApp_Other
Interested to know if this is what people are experiencing? Will I need to emigrate before transitioning to an ebike in my retirement? 😁
 

UphillSlowly

Making my way slowly uphill
That's a good question.
Personally I only ever use my ebike when the weather is dry.If it's wet I use my ordinary bike.

Better for keeping yourself warm I suppose 😉
 

albion

Guest
I added the bold word 'Why are so many owners of electric bicycles complaining that their Bosch motors need to be replaced so often....
Some owners say they’ve been told by Bosch not to ride them in wet conditions, which is clearly absurd.....
He says some of the first-generation motors had experienced problems caused by water, but later models had been enhanced with improved seals and bearings. “The latest units are protected against dust and splash water, according to protection class IP54, and most error codes caused by magnetic interference disappear on restart." '

Yet here, explaining IP54 we get https://www.ledlightexpert.com/waterproof-ip-rating
'What is IP54? – This rating indicates that an electrical enclosure is protected from limited dust ingress and water spray from any direction. IP54 lights are widely used for indoor applications such as lamp post lighting. They should not be exposed to rain. '.

So Bosch cannot really be exposed to much rain. Bosch themselves appear to be magnifying the problem though at least the Guardian did obtain a comment.
 
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johnnyb47

Guru
Location
Wales
Do you think mid drive motors in general get a harder life than hub drives.There right in the firing line of water spray coming off the front wheel.A hub drive is a little more protected cycling in wet weather
 

albion

Guest
The one owner I know well, a fellow employee who used to commute on her Bosch, found it too unreliable. A replacement Bosch itself got replaced by an electric motorbike. Maybe it was the very wet commuting.
 

chriswoody

Legendary Member
Location
Northern Germany
Not possible anyway if Bosch won't sell spares.

In the video I linked to, the start of the chain of events that led up to the death of the motor, was caused by the owner failing to replace a bearing that the axle ran through. This bearing started to disintegrate and then the seals failed and started to let water in. The water then corroded the PCB to the point where it failed.

The bearings are a serviceable item which a competent bike shop or Bosch service centre can do. It's an interesting video that explains the problems and what led up to it and how it was an avoidable situation if the owner had replaced the bearing early enough.

The whole issue of lack of water proofness is an interesting one, looking at the ebike motor centre's website they have this to say about waterproofness of the motors:

"Is my motor waterproof?
The answer is, probably not. Currently, it would be commercial suicide for ebike motor manufacturers to properly seal a motor because this would lead to added friction and lower battery range. This does not look good on comparison charts when people are deciding which bike to buy. Most road bikes don’t require seals and mountain bikes make up about 10% of the market. Get the picture? Most current bike motors rely on the bearings’ dust seals rather than any dedicated water seal. This situation is good enough for most road bikes but bikes used off road will struggle."

It's certainly opened my eyes a bit and given how popular EMTB's are here in Germany, I wonder how many folk are aware of the potential issues when you use them in their intended way?
 
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