How long should my ebike chain last?

[John F]

it seems to me that chain wear varies from bike to bike.
Chains on crank drive bikes is an essential component and should be covered by guarantee.Any good supplier should replace it for you FOC.

Agreed. It cannot be classified as a "consumable" when it's lifetime falls a lot shorter than what an owner would reasonably expect. If a new cars gearbox failed after 5 months there would be an outcry.

 

[John F]

that is true...

in ours it says this:

Exchanging Intervals for Chains and Cogsets
Chains should be renewed after 1500-3000 km in order to avoid unnecessary wear of the chainrings and therefore increased costs! The chain’s mileage de- pends on the use-intensity and the care. Let your KTM dealer check the chain and the cassette regularly�

but that doesn't mean you can claim for a new one if yours doesn't last 1500km.

So at what mileage would you suggest it would be reasonable to claim?

 

[KTM Bike Industries UK]

firstly can I just make it clear that I'm replying as someone who's working in the bike industry for 20+ years and not as someone who works for a chain company.

its not reasonable to claim any mileage. I've had chains last 1 ride, ie under 30 miles. This is because it snapped under load and then I refitted the pins incorrectly because I was doing it in cold and mud. By the end of the ride the chain was a right off.

So I'm afraid there is no mileage really that you as a customer can expect a chain to last. You just have to keep an eye on it, use a chain wear indicator to check it, and replace it when it needs replacing.

Comparison to a car gear box isn't valid, its more like comparing it the the brake pads on your bike.

Col

 

[John F]

I'd love to be able to agree with you, but I'm afraid there isn't an average, and as its a part that is easily damaged by riders changing gear badly, not looking after it, taking the wheel in out, riding in a massive gear etc etc. I'm afraid you'll never get a brand of chain offering to warranty their product against wearing out.

we've had a customer recently contact us (not eBike customers) because their dealer wouldn't warranty their cranks because the paint had worn off where their shoes rubbed it. I'm afraid wearing a chain out comes under the same category.

Its not a manufacturing fault, or indeed one that any customer can reasonably claim or prove how many miles they have done, so no chain brand will warranty one for wearing out, especially on a crank driven eBike.

Col

I'm not expecting my chain to never wear out!

If its not a manufacturing fault, then it's a design fault because in my view it will not meet the Sale of Goods Act as being fit for purpose. It should NOT fail after 5 months. I've just paid £33 for a new chain and cassette - an expense that I never imagined I would have after such a short time of careful riding and weekly chain lubrication. I suspect many other riders would be of the same opinion

 

[John F]

You can't use the 9 or 10 speed chains on your 7 speed derailleur. Not only are they less strong, they are too narrow and will not sit down properly onto your wider sprockets. The internal chain width of 9 and 10 speed chains is generally 11/128" (2.18mm) rather than 3/32" (2.38mm).

My suggestion is to use the highest quality 7/8 speed chain that you can buy, but not the Rohloff 24 carat gold plated one at £124.99 of course. KMC's equivalent of their recommendation for your bike is the X8 series. One problem to watch out for is that standard chains have only 114 or 116 links, too short for you, and that's true of the KMC X8. I tend to buy two of a brand/type that I can consistently get and use one for add-on bits for each successive purchase.

Here's the complete size listing:

Trade bikes = 5/32" chain roller/sprocket teeth width

Hub and Single gear = 1/8" chain roller/sprocket teeth width

Up to 8 speed derailleur = 3/32" chain roller/sprocket teeth width

10/11 speed vary by maker, so for all derailleurs it's best to measure the overall chain width:

3-8 speed - 7.2mm (all brands)
9 speed - 6.8mm (all brands)
10 speed - 6.2mm (Shimano)
10 speed (narrow) - 5.9mm (Campagnolo)
11 speed - 5.5mm (Campagnolo)

Bicycle chain pitch (rivet centre to rivet centre) is always 1/2".

Good info thanks

 

[KTM Bike Industries UK]

I'm not expecting my chain to never wear out!

If its not a manufacturing fault, then it's a design fault because in my view it will not meet the Sale of Goods Act as being fit for purpose. It should NOT fail after 5 months. I've just paid £33 for a new chain and cassette - an expense that I never imagined I would have after such a short time of careful riding and weekly chain lubrication. I suspect many other riders would be of the same opinion

what did the shop say you bought it from?

you shouldnt need to replace the cassette if you replace the chain at regular intervals.

5 months of use means its not a manufacturing fault, and also is fit for purpose.

it might have just been one particularly wet, gritty road ride that killed it.

and if you're only lubing it weekly, that could be the problem. You should be doing it cleaning it after most rides and lubing it a lot over the winter.

What sort of lube are you using? some attracts more grit that can cause premature wear.

 

[John F]

As Dave has indicated earlier though, they are a consumable so not a normal warranty item. On a crank drive e-bike the usage is essentially abnormal for a bicycle chain, which weakens any claim.

Well no, because if it was abnormal, then the chain wasn't fit for purpose in the first place.

 

[John F]

what did the shop say you bought it from?

you shouldnt need to replace the cassette if you replace the chain at regular intervals.

5 months of use means its not a manufacturing fault, and also is fit for purpose.

it might have just been one particularly wet, gritty road ride that killed it.

and if you're only lubing it weekly, that could be the problem. You should be doing it cleaning it after most rides and lubing it a lot over the winter.

What sort of lube are you using? some attracts more grit that can cause premature wear.

Yes the supplier is looking into this.

I wouldn't have thought that you could over lube a chain? I admit to not not cleaning it after every ride, though as I said it's only really been used on fine days. I use White Lightning Clean Ride. My method was to first apply some car engine oil onto each link, and wait a while till it penetrated the links. Then wipe it off and apply the Clean Ride. I did this every 1 to 2 weeks.

It's only been in the rain 3 times and on some muddy bike tracks a few times. My expectation was that the wax coating should fend off any nasty stuff.

After comparing the new cassette with the old one, there wasn't a huge difference I must say, though I'm not an expert on what is acceptable wear - I just replaced it on the safe side.

 

[John F]

john,
does the chain sit on the rear cogs properly?
if it does not, how many links are out?

colin,
I think manufacturers should tell their customers what is the average expectancy for the chain on a crank bike, for example, 1200-1500 miles for 90kgs riders. You ought to know the figure.
If the wear is substantially above average, then it's only fair that it's replaced FOC for the customers.

Trex
Yes the alignment was ok, although I haven't needed to tweak it.

 

[flecc]

Well no, because if it was abnormal, then the chain wasn't fit for purpose in the first place.

I'm afraid yes, it is abnormal. Bicycle transmissions and chain sizes are designed for bicycle rider power, typically for a fit person 200 watts for an hour continuous or 100 watts for 5 hours. Shoving up to 800 watts or over 400 watts continuous through them is not normal for the design.

So yes, bicycle transmissions are not fit for purpose on crank drive e-bikes which is what I meant. It's not just derailleur chains, Shimano discontinued their 4 speed gear hub after they were wrecked by the original Panasonic crank units and some of today's crank drive units can exceed the stated torque limits for Shimano's current hub gears, leading to problems.

Hence my earlier comment that the best option is a NuVinci gearhub with a larger size chain or toothed belt drive.

 

[Deleted member 4366]

A wider chain wouldn't be any stronger. In fact it would be weaker if it were wider than the sprockets. To be longer lasting, it would need bigger (diameter) rollers, or to be made of a tougher material, or have special design features to hold the lubricant in and the dirt out.

 

[flecc]

I disagree, a wider chain on a correct width sprocket gives greater bearing areas to both roller and rivet and thus is longer lasting. Trade bike 5/32" chains to handle much greater loadings are stronger than 3/32" or 1/8" chains for example.

 

[mike killay]

Sounds like this is an area where designers really need to concentrate rather than the fanciful 'artistic' frames etc. that they do produce.
For a crank driver, I would prefer 4 well spaced derailleur gears with a wide chain.
If crank drivers continue to increase in popularity, I think that there would be a market for Shimano, SRAM etc.

 

[flecc]

Sounds like this is an area where designers really need to concentrate rather than the fanciful 'artistic' frames etc. that they do produce.

Definitely. The problem holding back Shimano is probably the still small size of the e-bike market. The exception, The Netherlands, isn't a problem for transmissions, partly due to the lack of hills and partly due to the Dutch in consequence mostly liking simple hub motors.

Now that that Shimano have their own e-bike system division with a crank drive, maybe that will stimulate them to design something specific.

 

[mike killay]

Definitely. The problem holding back Shimano is probably the still small size of the e-bike market. The exception, The Netherlands, isn't a problem for transmissions, partly due to the lack of hills and partly due to the Dutch in consequence mostly liking simple hub motors.

Now that that Shimano have their own e-bike system division with a crank drive, maybe that will stimulate them to design something specific.

The strange thing is that on my Tonaro, it has always been the 11 tooth sprocket that wears and causes chain skip. I only use this gear on the flat, the really tough work (and consequently high wattage) is on the larger sprockets going up hills.

 

[mike killay]

When we talk of chain wear, exactly what do we mean?
Do the fish plates stretch, or is it a matter of the rollers getting smaller, or the rivets reducing in diameter?

 

[KTM Bike Industries UK]

the chain gets longer, because the plates stretch.

 

[Deleted member 4366]

Chains wear on the inside between the rollers and the

Well no, because if it was abnormal, then the chain wasn't fit for purpose in the first place.

It's a bit like buying a torch with a battery included. You can't make a claim that the battery is defective because it ran out after a few hours use. The chain is a consumable item just like a battery.

 

[RobF]

I've just paid £33 for a new chain and cassette

What sort of bike is it?

I reckon the original equipment chain was about the cheapest KMC make, say retail about £6.

My Rose has a Shimano Dura-ace chain which retails at about £35.

Spending £33 on a chain and cassette is not going to get you anything of good quality, so I'm afraid the problem will recur.

 

[John F]

What sort of bike is it?

I reckon the original equipment chain was about the cheapest KMC make, say retail about £6.

My Rose has a Shimano Dura-ace chain which retails at about £35.

Spending £33 on a chain and cassette is not going to get you anything of good quality, so I'm afraid the problem will recur.

Woosh santAna cel. My new kit is basic Shimano kit i think. Maybe 2 ways to go. Buy cheapest chains and discard after 200 miles say or go for the most durable and expensive and hope it pays for itself. Trouble is how would I know?