Not a great start with e-bikes. Chain continually jumps off the front sprocket.

[Vim Fuego]

Chain in lowest gear, the derailleur should ideally be at a right angle to the horizontal plain. It is clear in this pic the chain is too short and the mech is being stretched/stressed.

Road test supports this, it appeared ok when I tested it, but under load on hills, there is some slippage. Putting the original chain back on and it's not slipping anymore.

I think I am going to keep an eye out for a 10 speed groupset with a better derailleur (one with a clutch and tension that's not total dogcrap like the one fitted) and a thinner chain, so it's less likely to lose tension and less likely to need me to come out and collect it in breakdowns.

looking around on eBay, a 10sp Deore groupset Inc lever with display, chain and cassette is about £130. I guess it's reasonably straightforward to swap over.

 

[GLJoe]

2/ Bearing in mind a pair of links have already been removed, and mostly solved the issue, it's clear the chain was too long. I have since discovered OEMs fit chains from a huge roll, not the preset lengths you buy in stores...

Don't assume the 'preset lengths' you buy in stores are the correct length!

I've ALWAYS had to remove a few links from 'standard' length purchased new chains.

 

[GLJoe]

Road test supports this, it appeared ok when I tested it, but under load on hills, there is some slippage. Putting the original chain back on and it's not slipping anymore.

This is common when you put a new chain on, but the cassette teeth have worn to the contours of the old, worn chain.
You probably now need a new cassette.

 

[Vim Fuego]

So some more on this. After the new (114 link) chain didn't work out,I gave the old chain a really good clean and lube and put it back on. We went on a 25 mile test ride last weekend and everything was fine.

Yesterday evening I got the call... Chains come off again.... Can you pick us up in the car... Grr.....

I have "borrowed" the narrower 11/128 chain from my Sduro 3, and confirms that if it comes off, it's recoverable roadside, as the chain is slimmer, it doesn't jam and need splitting. It also appears to run just fine in the narrower format (thanks for whoever mentioned this). I have ordered a narrower new KMC X8 11/128 from Amazon, here today.

I'm also getting more and more convinced that this bottom of the range Shimano rear derailleur simply isn't suitable for ebikes, and it was a corner cut too far for their entry model.

I'm looking at replacement of the groupset with something better, at minimum a clutch on the rear derailleur to know this issue on the head for good.

Would this be suitable??

https://www.amazon.co.uk/JGbike-Sunrace-Cassette-12-Speed-Shimano/dp/B084KTRLXK?th=1&psc=1

 

[sjpt]

I'm also getting more and more convinced that this bottom of the range Shimano rear derailleur simply isn't suitable for ebikes, and it was a corner cut too far for their entry model.

Probably should be 'not suitable for crank motor ebikes'.

 

[georgehenry]

As your problem seems intermittent, I would put a narrow wide chain ring on the front, as for me this completely stopped my chain getting dropped off.

Narrow wide chain rings are also more substantial and longer wearing.

 

[GLJoe]

I'm also getting more and more convinced that this bottom of the range Shimano rear derailleur simply isn't suitable for ebikes, and it was a corner cut too far for their entry model.

I'm not saying you're wrong on the above, but I'm struggling to work out why this would be the case?

I mean ... when exactly does the chain come off? how is the bike being ridden at the time ??

 

[Nealh]

Can you not fit a chain keep as basically that is what a derailleur is.

Manually check every chain link for either kink in it self or a stiff pin joint.

 

[guerney]

Dahon saw fit to fit something which looks like this to my 8 speed - good job too, as the chain jumps off without it:

1PC Bicycle MTB Chain Guide Guard Frame Protector Road Bicycle Mountain Bike- | eBay

Adjustable clamp size: 39-42mm. Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Do not take off the chain;.

www.ebay.co.uk

 

[guerney]

Can you not fit a chain keep as basically that is what a derailleur is.

Manually check every chain link for either kink in it self or a stiff pin joint.

I always had problems joining links myself - it doesn't take much misalignment for the pin joint to be stiff, also hard to identify... which is why I always use a "Missing link" these days.

 

[guerney]

???

Bicycle Bike MTB Chain Guide Mount Aluminum Alloy Chain Tensioner MTB Tools UK 8257247828511 | eBay

Ultra-light high-strength AL7075 aluminum alloy, high-quality CNC processing, light weight but high strength. Material: Aluminum alloy, Nylon. Material: 7075 aluminum alloy CNC; nylon. Spec: φ35mm~ 31.8mm mount / E type mount.

www.ebay.co.uk

 

[Vim Fuego]

???

Bicycle Bike MTB Chain Guide Mount Aluminum Alloy Chain Tensioner MTB Tools UK 8257247828511 | eBay

Ultra-light high-strength AL7075 aluminum alloy, high-quality CNC processing, light weight but high strength. Material: Aluminum alloy, Nylon. Material: 7075 aluminum alloy CNC; nylon. Spec: φ35mm~ 31.8mm mount / E type mount.

www.ebay.co.uk

None of these bodge tensioners/retainers will fit a proper mid-drive ebike... The motor case rises much higher than the front sprocket. They also don't address the root cause.

My Sduro 3.0, bought at the same time, with 10speed Deore groupset has so much more tension and nowhere the amount of chain bounce (even with the clutch off). Hence my feeling all these problems are related to the crappy rear clutchless Acera derailleur they fit on the 1.0 spec bike.

 

[guerney]

None of these bodge tensioners/retainers will fit a proper mid-drive ebike... The motor case rises much higher than the front sprocket. They also don't address the root cause.

My Sduro 3.0, bought at the same time, with 10speed Deore groupset has so much more tension and nowhere the amount of chain bounce (even with the clutch off). Hence my feeling all these problems are related to the crappy rear clutchless Acera derailleur they fit on the 1.0 spec bike.

My bike's design includes this part:

Tern/Dahon Chainwheel Guide

If you could watch your chain, you’d see waves of energy literally bounce the chain as it moves up and down the cassette or when riding on rough roads. With the shorter chainstays of folding bikes, the waves just get amplified in size. In order to help prevent the chain from derailling the...

foldingbike.biz

It keeps the chain from jumping off, with or without a Bafang BBS101b mid drive kit installed.

 

[Vim Fuego]

Interesting, exact mirror of the problems I am facing.... Too long chain originally fitted, jamming, roadside recovery...

UKC Forums - e-bike woe

www.ukclimbing.com

 

[Vim Fuego]

Much, much later followup. Nothing I ever tried fixed this fully, the only solution was to throw the 8-speed entry level groupset in the bin, and buy a decent, mod-ranger 10 speed groupset (the same as what's on my bike).

The bike has done 4000 miles without a single issue. Clearly Haibike cut a few corners too many to make the SDuro 1.0 pricepoint. They also washed their hands of the problem, and didn't want to know, so Haibike, and their parent can go fsck themselves when it comes to future replacement.

Happy we got it fixed, unhappy it cost £200 in parts, and being abandoned by the manufacturer.