Electric bikes chains v Gates drive and IGH

[Canardly]

Retired friends of mine having electric bikes often complain about the frequent servicing requirements for replacement sprockets and chains. The obvious alternative is a Gates belt drive and internal gear hub. Are there any strong opinions out there either way?

[T42]

Hub motors don't put heavy stress on transmissions. My current cassette has 12,486 km on it and the two chains I alternate between have ~6000 and 8000 km respectively. Wax lube, swapped over every 500-700 km and I suspect the km for one got added to the other and they're on ~7000 each.  Chain stretch is under 0.5% according to Park's wee bit of metal.

Using a mid-drive motor and not pedalling very hard is probably the culprit.

[Kim]

Surprising how few high-end mid-drive e-bikes (the sort of thing that have electronically-shifted^[1] Alfine or Enviolo hub gears) don't use belt drive.  They're already making a custom frame for the motor and battery, so you'd think a wossname for the belt would be easy.


_{[1] There's a lot to be said for the motor controller knowing when you're changing gear, as it can back off the power to reduce stress on the drivetrain.}

[yoav]

I'd say if you can afford the extra for a hub gear/belt drive combo on your eBike then go for it. That is, unless low weight is your priority. The latest carbon frame eBikes with derailleur gears are about 12kg whereas an aluminium eBike with a hub gear is around 20kg.

[hubner]

Aren't Gates belt drive replacement parts really expensive compared with chains and sprockets? And they're proprietary.

The main attraction of a belt drive is no dirty chain, but then IMO a hub gear with a fully enclosed chaincase ought to be more suitable for an utility ebike.

[Paul H]

Using a mid-drive motor and not pedalling very hard is probably the culprit.

That describes how I ride the derailleur geared, mid motor Bosch E-bike, I use it for deliveries rather than fun, though the two do occasionally coincide.  it's also the constant stop/start riding that is supposed to be the worst on drivetrains.  Then add to that it's all weather use and lack of cleaning...
Yet I'm getting the same life, as far as I can tell, from the chain and cassettes as I did on the non assisted bike used in exactly the same way for three years.  I think the idea E-bikes are hard of drivetrains is overplayed.   

[Asterix, the former Gaul.]

I have a used a Trek Soho with hub gears and belt drive for about 8 or 9 years.  It only had one problem which was the aluminium sprocket not being tough enough and it had to be replaced with stainless steel.  I would not swap it it for an open chain drive as the belt simply does not pick up dirt and grit like an unenclosed chain.  Chain cases may be the answer but they can be problematic over time and abuse.

[Duckfoot1606]

Recently I was on a train in Germany and got into conversation with a cyclist on his latest tour who had a belt drive bike, he mentioned that the drive train was basically maintenance free and had done 4 years and around 15000km without any attention.

A

[tom_e]

Not had an issue with chain-driven mid-drive Bosch.  It wears chains, but only because it covers plenty of miles.  I think the smooth torque probably wears less badly than a human pushing pedals, but it still wears.

The hub gear on it, on the other hand, makes any time you do need to remove the wheel MUCH worse than a derailleur.  I know those things are popular on here, but I would not buy again.

[T42]

That's certainly true of mine, it's a right PITA.  OTOH with Schwalbe Duranos and Slime tubes I've only had to do it once at the roadside in 2 years.

What I find most annoying about my set-up is losing a bottle cage, with the extra weight of carrying a spare battery if I want to go over 100k coming second.

[Paul H]

The hub gear on it, on the other hand, makes any time you do need to remove the wheel MUCH worse than a derailleur.  I know those things are popular on here, but I would not buy again.

If removing the wheel is a pain, set your bike up so you can fix punctures without removing it.

[rogerzilla]

Three problems with belt drive;

1. The frame needs to come apart somewhere to allow belt changing/fitting
2. Price*
3. Slightly lower efficiency

*Gates make some pretty inexpensive accessory belts/cambelts for cars - the huge serpentine belt on my MX-5 was about £30 -so this is either poor economies of scale, or just gouging cyclists.

[Kim]

Three problems with belt drive;

1. The frame needs to come apart somewhere to allow belt changing/fitting
2. Price*
3. Slightly lower efficiency

None of which would appear to be a problem for high-end e-bikes.

[tonycollinet]

When I get an E-bike (hopefully not for a while knees willing) It'll be belt drive.

I have a belt drive commuter and once fitted with the good belt hasn't needed any attention for years.

It has an alfine 11 speed hub, and removing the wheel is not much worse than for a derailleur: 5 seconds extra to unhook the gear cable, and you need to carry an appropriately sized socket and bar to undo the nuts, rather than having quick release.

[Sergeant Pluck]

When I get an E-bike (hopefully not for a while knees willing) It'll be belt drive.

I have a belt drive commuter and once fitted with the good belt hasn't needed any attention for years.

It has an alfine 11 speed hub, and removing the wheel is not much worse than for a derailleur: 5 seconds extra to unhook the gear cable, and you need to carry an appropriately sized socket and bar to undo the nuts, rather than having quick release.

I think it depends on the frame design - on the Tern I used to have, the way the hub was orientated in the frame made unhooking and refitting the chain quite tricky especially at the roadside in the dark. Very difficult to get a view of the area concerned without turning the bike upside down. Might be different for the 11 speed, but for the 7 speed I needed a small hex key (?0.5mm, can’t remember) to do so.

Getting back to chain wear, not a problem at all for a hub gear, but much worse for a derailleur-equipped e-bike.

[Asterix, the former Gaul.]

WRT fitting the belt, I notice my frame triangle has a gap, filled by something or other, probably to allow the belt to be added. I don't know if this is a removable part. The belt seems in good condition despite the bike being many years old now.  The lower efficiency is not an issue on a town bike.