eBike Motor Failures ... Details please?

Not had a failure on my e8000 motor yet(2k miles sor far) but a mate has had his '20 reign e in the shop now at least 5 times in the year he's owned it.
At least 4 button control modules
1 motor due to cracked motor casing
Currently waiting for new wiring and battery due to water ingress

Bosch cx gen 4 :failed after 550 miles, just turned it on to go for a ride and it threw a 550 error, which according to the manual is an improper load error, but from chatting to the bosch dealer it means a short circuit was detected. Motor still ran fine, no untoward noises etc, but threw the error every time it was switched on. Some speculation on another forum that 550 errors are caused by water ingress corroding the circuit board inside the motor casing. One chap with the same error took his motor apart and found water and noticed corrosion on the circuit board.

For mine, Bosch replaced with a new motor under warranty, but won't say what caused the fault.

Motor was used in all conditions, but never submerged and never jet washed.

If there’s water in your washing machine motor, then you have a serious problem!

Also ebike motors are not just motors and gears in a casing, there is a whole load of electronics in there, micro processors, sensors etc etc.

So when people say the motor failed, they mean the drive unit, which has the motor, the gears, and all the electronics and sensors in a single unit.

I reckon when water gets in, it's the electronics that fails first in most cases, not the motor itself.

I have to say, I'd be surprised if the boards inside the motors don't have some sort of conformal coating on them - I believe the main board inside the Levo batteries does, so I'd imagine the Brose/Specialized motors would at the least.

Have a look towards the middle of this thread for some photos of the inside of bosch gen 4 Cx drive unit and corrosion on the pcb

https://www.emtbforums.com/community/threads/bosch-gen-4-error-code-550.13197/

My mates Levo has been in and out of dealers quite a few times, for a 1 year old bike, with "motor" issues. After getting a Christmas tree's worth of lights going off they found moisture and dirt in the compartment where the circuit board was housed. All replaced and repaired under warranty, but to be honest with how we (the MTB community in general) ride our bikes and the UK weather we shouldn't be surprised at the number of this type of problem. Add to that hose pipe cleaning, or god forbid a pressure washer (!), and water ingress is inevitable I think.

3 Spesh bikes

2017 Levo, new motor due to water ingress, my fault due to bad washing technique, bearings were rough and notchy, replaced under warranty via the dealer

2018 Kenevo, hard pedal strike, crank arm could be moved in and out, no idea what had broke, even Spesh dont know as they are not allowed to open the motor up, they have to go back to Brose to be inspected, motor was replaced under warranty via the dealer

2020 Levo, riding along and all of a sudden no drive and a screeching noise, dealer said it was the sprag clutch and drive belt, which is a known issue and a new updated motor with improved belt and sprag clutch fitted under warranty, also Spesh say the new motor will have a 4 year warranty from date of purchase of the bike to give me peace of mind

Every time Ive had a motor replaced Ive only been off the bike for one day, the motors were replaced within an hour of arriving at the dealer, along with fitting the new motors they also check the whole bike over including the pivot bolt tightness and adjust anything that needs it and then test ride it to make sure all is OK before handing it back

Cant beat the service Chris Reilly and the team @Berkshire Cycles offer, a great warranty policy and great dealers are key when it comes to e bikes

Had a Bosch Gen4 fail, couldn't be fixed and refunded due to no bikes available at the time of the covid rush last year, went for an e-reign pro, motor, battery, etc has been faultless, but i think i've broken every other bit through crashing, jumping and more crashing, i've read all the water ingress stuff, so i pushed the bike at the start, and that was in the wet months over in FoD and other places, it still running, but as always, there does not appear to be a trend, some fail, some don't, can't see QC being an issue, but something happens where some are just basket cases, and others just bimble on.

Merida with E8000: Torque sensor in motor suddenly died during cold weather after 2.5 years/8500km. Motor replaced under warranty. Only other issue I've had is I snapped the remote cable squashing it in the car.

Levo with Gen1 Brose: Motor still fine after 3 years/6000km. Has broken 2 wiring looms though, they bend too tight when you have to unplug it to charge and it breaks the wires. One of the battery LEDs has failed due to water, still functions fine though.

Are road going ebikes with full guards having failures as well?

Kona Remote Control 2 motors in 2 years. The last time an error message came up I switched it off then back on again and without warning the bike shot across the garage floor and slammed into one of my other bikes. Fair shook me up I don't mind admitting. Replaced by Bosch, I got in touch with them, they were really concerned (they weren't on their own!) Dealer was mortified. After investigating all Bosch could tell me was quite a few errors showed up and I believe water ingress. I don't use a pressure washer just a very gentle almost a dribble hose and obviously don't point it at the motor 🙄

Are road going ebikes with full guards having failures as well?

Anecdotally, they appear to much less likely to fail, there are commuter ebikes with 10s of thousands of miles on the original motor.

Well this thread is suitably putting me off owning one now.
Thanks for saving me money!

Levo with Gen1 Brose: Motor still fine after 3 years/6000km. Has broken 2 wiring looms though, they bend too tight when you have to unplug it to charge and it breaks the wires. One of the battery LEDs has failed due to water, still functions fine though.

I was happy to buy used out of warranty tbh, as the industry I work in means that I can have a crack at sorting any issues myself anyway.

I have had issues with over-run. The motor not stopping when I stop pedalling. Specialized Levo. I had the motor replaced. Twice. The 3rd one hasn't done it yet.

I've skim read many threads and from my understanding a lot of it is water ingress, from jet washing, rock strikes damaging the casing, or worn bearings causing too much play.
But there was one guy who dismantled his shimano motor and found a magnetic sensor ring had cracked in two and he got a replacement from someone breaking old motors down for parts.
Someone here also managed to wear out a plastic gear out (after 7500 miles of derestricted riding):

There are facebook groups for various motors. EMTB Forums is also a good source of info.

I went through 3 Gen 2 Bosch DUs in 2500 miles. All failed in the same manner; failed main bearings due to shit design and stupid small chainring forcing grit into the bearings. Pretty much irrelevant now as a point of failure as the DU has been superceded by the Gen 4. None of the failures were ride ending. All bar the first were 7 day turnaround, the first was 4 weeks.
I had an erroneous 504 error on my Gen 4 (tuning detected) it was a known problem that a software update sorted. I'm now at about 1900 miles and have suffered no other issues.

My lockdown riding buddy had a belt failure on his 2019 Levo last weekend. That's the third ride ending failure in 2700ish KM. 9 days and counting on this repair.
Another Levo riding acquaintance has had more motors than I've had hot dinners, the best being an updated motor that lasted 2 rides and 1 mile. Plus several power cables and TCUs. He's lucky; he's an executive with a company car and an office fairly near Berkshire Cycles so all his issues have been fixed in a day.
2018 Kenevo 600km, seized solid. LBS quoted 6 weeks as they were busy so he dropped the motor himself and got them to send it back. Middle of Loockdown 1.
Different 2018 Kenevo, also seized solid, not sure of the KMs on that one, but more than the first. 5 weeks for this one, I think. Pre-Covid.
2017 Levo motor died, 9 weeks to get it sorted. Blamed on Covid by the LBS.

My bosch gen4 is on 1000 miles, my previous gen3 still in use with a mate at 2000 miles. Neither have been jet washed and the gen3 was regularly repacked with waterproof grease. They’re not designed to be jet washed and you see loads of folk doing it.
I briefly had a specialised levo amd that toasted it’s first motor at 150 miles, the second went shortly after and the bike was rejected.

A lot of ebike problems are poor riding technique, changing gear under load and poor washing technique.

@couchy agreed... I see so many people pushing the harder gears and pedalling at low cadences. If only they read the manuals/cared to do any research I think there would be a lot less bikes needing warranty

Looks like water ingress  is the cause of most people's woes and that electrical component failure as a result is the show stopper. My next question would be where do we think it's getting in? Is it purely via the crank shaft I wonder? If it comes through the casing then that's a bit rubbish so my guess is via the shaft.

If it's through the shaft seals is there anything that can be done to help prevent this - should grease be applied arouhd the seal externally? Plenty of GT85 after a wash/wet ride (or none - does it make it worse by dissolving the grease inside???)....

and pedalling at low cadences.

Out of interest, what's the problem with this?

It's the main signature I used for spotting an E-bike rider ahead.

So I’ve been looking at an ebike with a Shimano motor which has a 2 year warranty. Does this mean I should be expected to pay £5.5k for the bike and then potentially after 2 years be left with a bill of approx £1,000 to repair and then have it happen again in another years time ?

Has anyone got data on e motorcross bikes? I’ve seen them take more hammer and washing than mtbs (apart from obviously they don’t have the pedalling complication/interaction)

Deffo no gt85, its a solvent and dissolves grease.

I don't think there's anything wrong with low cadences on an ebike, as pointed out its mainly water that causes the issues.

As I understand it (*and I’ve been known to be wrong) but one reason for specialized failures (belt), was razz down hill at v vhigh mph in top gear, and then go into a full power slow steep climb without changing down and overload system. It sounds a bit like lugging a car to me and I’d suspect that’s not good for any ebike.

So I’ve been looking at an ebike with a Shimano motor which has a 2 year warranty. Does this mean I should be expected to pay £5.5k for the bike and then potentially after 2 years be left with a bill of approx £1,000 to repair and then have it happen again in another years time ?

Short answer, yes, however someone on the EMTB forum has recently had a new Shimano motor under warranty at 2.5 years old so it seems there's some leeway.

Does this affect the repairability issues of ebikes?

New EU rules have been introduced that require manufacturers of electrical goods such as fridges and televisions to make their products repairable for at least 10 years after first coming to market. The rules are designed to enshrine circular economy practices into law and reinforce consumer rights to repair products.

So I’ve been looking at an ebike with a Shimano motor which has a 2 year warranty. Does this mean I should be expected to pay £5.5k for the bike and then potentially after 2 years be left with a bill of approx £1,000 to repair and then have it happen again in another years time ?

I'm looking at a replacement for my Giant Reign E pro, that suffered from 5 electrical faults and was returned for refund.

I'm not buying a bike with a Shimano motor. If you shoot over to Performance line the only motor they don't touch is the Shimano one. I think he explains in a YT video that this is because of the way the electronics/circuit board are potted and in the way (or something like that). Either way, unless somebody can come up with an out of warranty cost effective repair for these motors I'd avoid them.

Having said that I'm sure somebody will see the lack of an aftermarket repair for the Shimano motors as a business opportunity. Or perhaps Shimano will offer an exchange motor at a reasonable price at some point in the future?

I don’t think there’s anything wrong with low cadences on an ebike, as pointed out its mainly water that causes the issues.

Low cadence + high load = elevated internal temps.

Over the four years of owning them I've seen it go from one or two out on the trails to now seeing the majority on the trails to be emtbs.
Being one that's always up for a chat its quite evident that there are alot now who not been satisfied with the power output are openly bragging they have deristricted them and constantly run them on Turbo
I'm sure that some of this must have an impact on reliability.

I can't see the need to derestrict. IMO people who do are looking for something different to what an ebike is designed to deliver. Riding in Turbo everywhere - WTF? I can only imagine they are blasting about on forest fire roads. The type of singletrack I am interested in would end as hospital at sustained speeds over 15.5mph.

I do most of my riding in Eco, and try to spin at 90 rpm. The Brose motor will tell Garmin via ANT+ what your current cadence is. I WANT my motors to last, and I don't set out to abuse them.

The sprag bearings in the Brose motors are rated to 250nm. The motor puts out 90nm. A 100kg rider (Max according to Specialized is 109kg) by bodyweight alone at 90 deg crank position on 165mm cracks can input 165nm. Already is is possible to exceed the rating of the sprag bearings Then there are the extra forces caused by the suspension action causing chain growth that will manifest itself as torque on the bb axle. The sprag bearings need to cope with 500nm IMO to be safe from damage from normal riding.

I cant see the need either. Most of my riding is in Eco and in the Peak. I'm suprized at the amount that have deristricted. I don't think it's just the area I ride in.
I also believe that by deristricting its got to put extra strain on the motor and the reliability of it.

I use my Levo in turbo loads, I’m basically all or nothing - full power or motor off! Riding up singletrack like that is v intense, so many corners you’d never noticed unpowered.

I suspect that destricting ebikes is a v bad idea for reliability - I’ve heard that one trick is to move the wheel speed sensor to the cranks. With a 15.5mph limited motor you get a burst of power and then you’re on your own and the motor gets to rest.

Derestricting doesn’t make any more power, you can load and stress your motor just as much in a restricted one. All the motor does is spin no matter what speed you are doing it doesn’t make any more power with the limits removed. I agree on a lot of trails 15mph is enough. But some fast trails are a lot more exciting at 25mph I can imagine 👍

I don't see the need to derestrict my own bike either given the type of riding I do. My main goal is exercise so I ride in ECO mostly (85% of the time according to the diagnostic report I got last week). Riding everywhere in Turbo sounds like it will shorten the life of probably most of the components on the bike actually, not just the motor. However Bosch do do a speed version  of the CX for countries where the limit isn't 25kph and I wonder what the difference between the two motors is (other than just software). I think if you de-restrict it they will be able to tell and you will have voided the warranty if it does break.

When you think about it e-bikes are fairly new technology so you’re going to get issues. The one common thing with each issue mentioned is the manufacturer, Shimano, Bosch and Brose have repaired or replaced under warranty. Which can only be a good thing. Got an E8000 motor on both e-bikes and had no issues.

I watched a Performanceline repair video and they reckoned it was pedal strikes that did for most of the spray bearings, just too much force going through it so they upgrade them when they do the repair. Seems pedal strikes are a common thing with ebikes. Not sure if its technique or what as they all seem to be putting shorter cranks on all the time. Haven't had this issue with my SL but that could be that the bb height on my analogue bikes are lower so I'm used to watching where I pedal.

This is something I've been thinking about lately too. My mate has Vitus with Shimano kit in he seems to be constantly having to get bits replaced on it due to faults or dead motors or whatever.

It must be frustrating for the owners, but also worrying from an environmental point of view.

I'm interested in the outright numbers. Could a survey be set up?

Those that buy an ebike and ride it all the time in eco why don’t you buy a normal bike ? Eco mode about offsets the extra weight and gives you little against a much lighter normal bike. If it’s about getting fit then ?

Folk seem to have some confusion over how an ebike works, you can still put in 100% human effort same as on a normal bike. If you ride an ebike and only go the same speed as a normal bike then of course they require less effort but if you go much faster than your normal bike you get a similar workout but the reward is much more speed. At my local trail centre I can compete the 6 mile blue route in 34mins on my normal bike, on my ebike it’s 19mins....that’s with me trying 100% so the motor assist gives me the extra speed it doesn’t reduce my effort. It also makes the trail very exciting and let’s a 50+ year old man go round at the pace of the quickest normal bike with a young athlete on it. I see no downside tbh

I do have a normal bike, as I assume most on here do, and also access to a few more. To me its just a different way of riding and in some instances let's me get out when time is short
As I said Eco most of the time. When I ride up the Beast it will be a mixture of Trail and Turbo.

If you shoot over to Performance line the only motor they don’t touch is the Shimano one.

No, they don’t do anything for the Dyname (Rocky Mountain) motor either.

Those that buy an ebike and ride it all the time in eco why don’t you buy a normal bike ?

Because I like the torque, I like the way it handles, I like the confidence it gives when exploring, I like the "tech" - loads of reasons really.

And like others have said I ride it mostly but not exclusively in ECO. 🙂

TBH an eBike is a game changer for people like me. 👍

My main goal is exercise so I ride in ECO mostly (85% of the time according to the diagnostic report I got last week).

Switch it off and get more exercise...

“Those that buy an ebike and ride it all the time in eco why don’t you buy a normal bike ?”

I often ride with the motor off (inc the odd gentle uphill) and use eco most of the time, I’m 61 and I want to keep active as long as I can. I still use my 2006 orange 5, I’m an natural xc bimbler (enjoying the scenery, etc etc as well as the trails) what the e does is it covers ‘bad legs’, massive headwinds, constant mud, being the wrong side of the hill when you’re knackered, and it lets me go exploring longer and further. It’s changed my riding, with age I tended to route plan, watch the distance and the hills, esp towards the end, now I just go exploring and thoroughly enjoy it

Age has stopped me playing football (2 hamstrings, too slow, so now I do walking football), hockey (to slow, no local vets club, stopped), floorball( ditto hockey), still do tennis but can’t cover the ground or last like the youngsters, mountain biking, well I’m able to exceed what I used to do in my 30s when I started.