E-bike durability

[Sergeant Pluck]

Strava says I’ve done 6500km on the Bosch Active Line driven Tern. 7 speed Nexus hub gears. There are starting to be some noises that weren’t there before from the motor region. I’m sure many of you have e-bikes with decent mileages on them now - what is to be expected down the line maintenance-wise? Or do they just tend to be a bit noisy once no longer new-ish?

Could it just be the chain / worn drive chainring? How long should I expect a chain to last on one of these? Not much poke from the motor but it does grind up some slopes every day. And I never clean it.

[Auntie Helen]

My motor is fine after 12.000 velomobile kilometres but the battery died and I had to buy another for 500 Euros which was sub-optimal.

[Sergeant Pluck]

Replacement batteries are a phenomenal price. That’s a great mileage.

Worrying rattly noises now, something’s not quite right. It could be something rattling around in the gear train in there maybe. It might be time to explore the world of e-bike motor wranglers.

Or it could still be chain, which I have cleaned but not yet checked for wear.

[Paul H]

That's not very many km's to be having motor problems, the bearings will wear, like any, but everything I've seen indicates they're of decent quality and well sealed. I'd be very disappointed if it were mine.  It wouldn't take much of a commute to be doing that in a year and Bosch are happy to warranty them for two, if that amount of wear was normal they'd never keep up with warranty repairs (Apparently they just swap out the motor)
I'm using mine for Deliveroo, only for the last 4 months, but that's nearly 5,000 km so I hope I'm right! I know several other Deliveroo riders working more than me and it always seems to be the battery that goes first, by which time the entire bike is usually a wreck. Even with the abuse I'd be surprised if anyone was getting less than 20,000 km, though some might just be tolerating some noise.
I'll follow with interest, though I'd be looking for other possible causes before deciding it was the motor.

[tom_e]

mrs_e has just had to replace the battery on a Bosch system.  She reckons something like 15,000 miles.  £450 sting, but the bike seems to work fine again now.

Rest of the bike seems ok, but that might hinge on usage.  Most of her commute is fairly flat and smooth until the last bit in town.  If you are bashing city roads for the entire mileage then the bike might be trashed faster than the battery?

[Sergeant Pluck]

I’m going to investigate it properly during the jolly festivities. Much of the commute is on bad surfaces and it has unfortunately been almost hub deep in water a few times. No play in the cranks so hopefully the crank bearings are ok. With the hub motor, Nexus 7 and chain tensioner its a very draggy drivetrain and hard to identify where rough running is coming from.

[Sergeant Pluck]

I'm using mine for Deliveroo, only for the last 4 months, but that's nearly 5,000 km so I hope I'm right!

I see many of the ebikes used by the newer delivery companies like Gorillas seem to have had things done. One came past me the other day on Putney Bridge at about 25 mph uphill while pedalling at about 1 rpm.

[Paul H]

No play in the cranks so hopefully the crank bearings are ok.

On the basis of having watched a couple of youtube vids, I have the impression that the crank bearing is the main one in the motor and the first to wear.  I was quite surprised watching one, when they opened up a well used E-MTB, it was spotless inside. 

[Paul H]

I'm using mine for Deliveroo, only for the last 4 months, but that's nearly 5,000 km so I hope I'm right!

I see many of the ebikes used by the newer delivery companies like Gorillas seem to have had things done. One came past me the other day on Putney Bridge at about 25 mph uphill while pedalling at about 1 rpm.

Yes. delivery riders are using all sorts, some legal, some less so. I'm not sure that's any different to any other users, I'm frequently passed by bikes on the cycle path going a lot faster than me and the rider not pedalling at all. Most of the platforms are promoting Eskuta, which is a scooter with pedals, you can lease or hire, I presume it meets the legal definition of an E-bike, you need to turn the pedals but it doesn't contribute much. 
https://www.eskuta.com/pages/justeat

[Sergeant Pluck]

The one I saw seemed to be a Gorilla branded bike.

Leaving delivery services aside, I’m surprised there aren’t more electric scooters in London generally. It would seem ideal for them.

[numbnuts]

Since 2004 I've gone through two 11 ah batterys and this year bought a 17ah at £400, the motor so far so good

[mzjo]

The Limoges municipal bike hire scheme has somrthing like 1000 -1200 e-bikes (can't remeber exactly how many but the fleet is big and only 50 unmotorised. Limoges has hills!). They seem to have no reliability problems but are used mainly by "non-cyclists" (including two of my neightbours). They have Nexus 7 hubs but also front hub motors and shaft drive. Is the fact that the Tern has mid-drive and a chain likely to be a factor?