Bosch motors & batteries

trialframe1

Finding my (electric) wheels
Jun 6, 2020
10
1
Just a general question - how reliable are Bosch components? I've had a few previous reliable ebikes - Giant LaFree & Kalkhoff Pro Connect Panasonic.
Thinking of changing to Bosch Gen 4 & would like to get feedback from existing owners.
 

Croxden

Esteemed Pedelecer
Jan 26, 2013
2,093
1,348
North Staffs
I'm on my fifth ebike with Bosch motors and so far, touch wood, no motor problems. I did manage to half knacker a Nyon unit during an upgrade to the soft ware, so I don't do the upgrades any more.
 

sjpt

Esteemed Pedelecer
Jun 8, 2018
2,471
1,927
Generally pretty reliable (there are posters here who disagree). We've just got one (2nd hand, now about 5 years old) and no issues. If there are problems they can be time consuming to fix, and very expensive if out of warranty.
 

Bonzo Banana

Pedelecer
Sep 29, 2019
123
69
I think off-road is where the problems are, they can have a tough life climbing steep ascents etc and do fail quite frequently and then you face huge repair bills as Bosch is pretty much a controlled environment with no 3rd party compatible components like batteries. I think for a general commuting bike they are a lot more reliable but then you ask yourself why do you need a mid-drive motor for a general commuting bike, I would of thought a hub motor more suitable for such a task. Surely everyone can agree its an expensive option, the bikes themselves are very expensive and even if the motor system doesn't fail you will get through a lot more drivetrain components. For many the motor systems have failed and I've seen frequent postings and remember mid-drive is only a small part of the market. Ebikes are dominated by hub motors, they are cheaper and more widely available. I don't know what the ratio is but its probably something like 20 to 1 in favour of hub motor ebikes possibly more.

Looking at Amazon for their best selling ebikes it looks like all currently are hub motors. However for ebike kits it looks to be a mixture of both hub motor and mid-drive kits being sold.


Just making the point Bosch ebikes sell in significant quantities and they probably dominate mid-drive sales on pre-built ebikes but they may still be small part of the overall ebike market and so really everytime you see a Bosch failure in a forum perhaps you have to imagine 19 more people also complaining to simulate what it would be like if mid-drive motor ebikes sold in the same numbers as hub motor ebikes. Many Bosch ebikes cost many thousands of pounds some well over £5k. Compare that to hub motor ebikes many of which are sub £1k. Bosch can still be commercially significant because of their far higher cost. It might take 15 entry level hub motor ebikes to get to the value of one typical Bosch e-mountain bike sold of a good specification in a specialist bike shop.

Looking at Parkers you have a starting price of about £400 for hub motor ebikes.

 

soundwave

Esteemed Pedelecer
May 23, 2015
11,202
4,644
DSC_0082_02.JPG

not bad for a 7 year old bike original motor with dongle still working and i ride it like i stole it every day on and off road and every bolt has lock tight on them ;)
 

MichaelM

Pedelecer
Nov 14, 2020
50
34
I suspect there aren't that many people who have proper experience of both mid-drive and hub drive, and purchase decisions are made on other criteria - price being a major one, A mainly cost-driven decision will tend to result in a hub-drive purchase.

I have never ridden a hub-drive - although I will when my conversion kit for the Brompton arrives. Meanwhile I continue to be astonished at the natural feel of the Bosch system, especially in Eco mode. 40% supplement to my own effort, if that's what it is, is transformational for me and so far has got me up all the nearby hills without me being prostrated through shortage of breath, using the appropriate gear of course. And it actually feels as if I am doing it myself, which I know is not the case.

I don't expect to be disappointed with the hub drive, but my expectations are that it will be a quite different experience, particularly without a torque sensor.

As to reliability - I doubt is there is much reliable and sufficiently detailed data in the public domain. I have some experience of fault and breakdown analysis in relation to domestic appliances. Shame it wasn't bikes:)

What you need to know is both the frequency and severity of breakdowns, and to have a fault cause analysis. Some brands have lots of mainly minor faults, some have very few but on average are very expensive to fix when they break down. The most interesting analysis I recall related to a white goods category. In both total repair costs, and frequency of breakdowns, the 'worst' brand was four times as bad as the best ones, and twice as bad as the average; and 80% or 90% of the breakdowns on that make had a single cause (identified by fault code) which, had it been eliminated, would have made that brand one of the most reliable.

The products in question were in the market 30 years ago so it wouldn't be very helpful or fair to reveal which manufacturer made them, but the point I am coming to is that until the analysis was done nobody would have guessed that the actual reliability of a well known, high volume brand was so (relatively) poor. The make was generally perceived to be OK - and had a high market share. It helped that the repair network was very good (and they obviously got a lot of practice). Good product support has a big effect on reputation, and sounds like an opportunity for Bosch.
 

Deno

Pedelecer
Jan 24, 2018
66
43
40
Dublin
I use a bosch Gen2 for commuting and it has 19k kms on it. Its been very reliable and has never left me stranded. The main motor bearing did fail at 18k and the motor was rebuilt by Performance Line Bearings and came back like new. The battery (powerpak 500) has lost a fair bit of capacity but its been charged twice a day 5 days a week and I also run a dongle so the power consumption is high.

There is a bit more maintenance required with a crank drive - I swap chains and cassettes myself and its no problem - I enjoy the work and like being independent in terms of bike maintenance. I prefer the feel of a torque sensing setup rather than a cadence sensing setup common on hub drive bikes (never ridden a TS hub drive). I also feel I need the exercise so pushing a bit with assistance is good. Another plus with a high mileage bike is that most components are the same as a normal MTB so wheel bearings, broken spokes etc. are serviceable locally. This is significant as I have found that this is where a lot of the wear/breakage occurs.

Very happy overall with the bike and its use, you hear a lot about premature motor failure etc. on Bosch but a lot of that was associated with Gen2. Also the sheer number sold is a multiple of other makes so there are bound to be more failures and you never hear about the motors that performed excellently for years. I also challenge the assertion made here that hub motors outnumber crank drives on commuter bikes, this is not my experience, most ebikes (in Ireland) are Bosch and I think that this is the case in continental europe also. I am aware that there seems to be more hub drive in the UK. Both systems have their pro's and con's - all bikes are a compromise ultimately. Its about choosing whats right for you.
 

Bonzo Banana

Pedelecer
Sep 29, 2019
123
69
I suspect there aren't that many people who have proper experience of both mid-drive and hub drive, and purchase decisions are made on other criteria - price being a major one, A mainly cost-driven decision will tend to result in a hub-drive purchase.

I have never ridden a hub-drive - although I will when my conversion kit for the Brompton arrives. Meanwhile I continue to be astonished at the natural feel of the Bosch system, especially in Eco mode. 40% supplement to my own effort, if that's what it is, is transformational for me and so far has got me up all the nearby hills without me being prostrated through shortage of breath, using the appropriate gear of course. And it actually feels as if I am doing it myself, which I know is not the case.

I don't expect to be disappointed with the hub drive, but my expectations are that it will be a quite different experience, particularly without a torque sensor.

As to reliability - I doubt is there is much reliable and sufficiently detailed data in the public domain. I have some experience of fault and breakdown analysis in relation to domestic appliances. Shame it wasn't bikes:)

What you need to know is both the frequency and severity of breakdowns, and to have a fault cause analysis. Some brands have lots of mainly minor faults, some have very few but on average are very expensive to fix when they break down. The most interesting analysis I recall related to a white goods category. In both total repair costs, and frequency of breakdowns, the 'worst' brand was four times as bad as the best ones, and twice as bad as the average; and 80% or 90% of the breakdowns on that make had a single cause (identified by fault code) which, had it been eliminated, would have made that brand one of the most reliable.

The products in question were in the market 30 years ago so it wouldn't be very helpful or fair to reveal which manufacturer made them, but the point I am coming to is that until the analysis was done nobody would have guessed that the actual reliability of a well known, high volume brand was so (relatively) poor. The make was generally perceived to be OK - and had a high market share. It helped that the repair network was very good (and they obviously got a lot of practice). Good product support has a big effect on reputation, and sounds like an opportunity for Bosch.
I think you have to look at the products themselves with regard engineering. There is very little to go wrong with a direct drive motor hub and they are typically very overbuilt and heavy however some are coming out of fairly basic Chinese factories but still overall a very reliable and simple motor. The geared hub have the addition of the 3 planetary gears and clutch system but still very simple but it does add in a wear and tear element to the design and then you get to mid-drive which is a very complex solution in comparison and has to deal with not only the motor power but the riders own power going through the gearing of it. It is extremely complex compared to a hub motor. Some mid-drive motors have belts and the controlling circuitry is within the motor assembly and water seals do fail on occasion. However typically mid-drive motors are manufactured by companies with higher engineering standards like Shimano, Yamaha etc. It would be amazing quite frankly if mid-drive motors could achieve the same reliability as hub motors. People buying hub motor ebikes may not be bike enthusiasts they just buy the bikes probably mainly for commuting and ride them and that's it really.

In many threads on forums like EMTB you get people complaining about how unreliable their ebike has been and then you get people who reply that they have had the same motor system with no issues however I did notice a thread about the Specialized Levo and Brose motor where no one came to its defence at all which I thought was quite showing of the issue.

I have a personal bias against Bosch as well, it annoys me how they control their market restricting spares and are preventing cheaper third party batteries etc. I've read so many horror stories of people having problems with Bosch based ebikes where they have had to put in huge sums of money to get them working again and some people have just given up as non-economic to repair. The bikes have dedicated frames to suit the motors so it can seem very wasteful when a bike fails prematurely and much of the bike has to be recycled early even though it was at a very premium price. Mid-drive can offer the best user experience while working but just seems like the worst possible experience when they are not. In contrast Bafang offers easy spares access, greater reliability, cheaper prices and can use existing frame designs. You can easily customise their mid-drive motors too. As I linked to earlier Amazon seem to sell a lot more Bafang mid-drive motor kits than actual mid-drive prebuilt bikes. Bafang would always be my preference for a mid-drive motor ebike.
 
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Reactions: Croxden

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