Crank drive pedelecs: chain wear and maintenance

[Tomtomato]

Hi,

There have been multiple posts on various threads regarding the impact of crank drive on the bike chain, given the torque of recent CD motors.

Would be good to get people's view on a common thread.

Specifically:

1) How long a chain is expected typically to last on a CD pedelec? Some people have reported 1,000 miles, others 6,000... Some people have reported chain snapping after 300 miles. Of course, actual usage and strain will have an impact, but it would be good to get some feedback

2) What sort of chain maintenance people do (as surely maintenance would impact lifespan)? Some people remove the chain, do a through clean/degreasing, and then bathing in oil. Others just rely on the original chain lubrication, and never use a degreaser

Thanks,
Tom

 

[Deleted member 4366]

A big factor is the weight of the rider. Light riders can cruise round on low power, so the stuff could last a very long time. Heavier riders will be pedalling harder and probably be using more motor power. The wear rate goes up exponentially with power through the chain.

One of the problems on this forum is that we often get statements of fact without the qualification that puts them in context. That's a real problem for noobs that take these facts at face value and base their decisions on them. I worry that people might be doomed to disappointment like this, which is the reason I'm often quick to challenge unqualified facts.

To answer your question on chain maintenace. I have a £7 chain on my bike from Ebay. It is branded, but I can't remember who's. It's done 2500 miles of moderately hard pedalling so far, and it isn't showing any signs of deterioration. I've never cleaned it, but I've lubricated it a few times. In the winter, I used White Lightening wet lube, which turned into valve grinding paste and gummed up my rear derailleur, so I wouldn't use it again. Now, each 500 miles, it gets a drizzle of hypoid 90 gear oil.

 

[JohnCade]

I have a Kalkhoff Impulse with Nexus 8 and changed the chain at 1500 miles using a gauge. It was stretched a bit by then but the sprockets were still good. I live in hilly country and like to go as fast as I can manage in as high a gear as I can uphill.

Hatti at Woosh posted here that the chains on the Woosh CD Sport should last about 1500 miles too.

Regarding lubrication I use dry lub, and have done so with my road bikes, and my motorbikes since it was available for them. Too much cleaning with solvents washes the manufactures lubrication out of the chain.

 

[trex]

woosh have upgraded the KMC chain on their Krieger and Santana CD to KMC X series. They have golden colour links and the links seem to be more supple than the previous Z series. Thay are supposed to last longer too.

 

[Croxden]

My Delite at 6000 + miles & I am 13 stone, more if I don't ride much. The Haibike chain gave way at 493 miles, split link failed. It is repaired and now over 1000 miles. I do give this a does of wax lube else it makes a fair racket on the silly jockey wheel.

 

[oriteroom]

One thing I hate is any 'feeling' or 'roughness' in the chain set. Like everything to glide along whilst cycling. Also hate rattles etc. Regularly use dry lube on all chains. Never trust gauges, prefer to rely on feel thru' the chainring. As soon as it feels lumpy, it's time to change. Note the early ProConnects had 1/8 x 1/2 inch chains, not 3/32 x 1/2 inch. First chains on these bikes only used GT85, useless compared with DryLube. Live by seaside, so agree with d8veh, wet lube soon turns to grinding paste with sand on the prom and from gravel on off road forest trackas

2008 Diamond ProConnect, alfine hub, changed at ~4000 miles, replacement still OK after further 4,500. Rear sprocket replaced at changeover.

2008 Step thru' ProConnect, alfine 8 hub, changed at 4,500 miles, replacement probably just about coming up after further 7,000 miles. Rear sprocket at changeover. Will need new rear sprocket at next change.

2010 ProConnect S, 9 speed Deore XT, first chain changed at 5000 miles, second one needed changing at 3500 miles. These are 3/32 x 1/2 inch. Both DryLube all the time. Not needed to replace sprocket set yet.

Weight: Mrs 'O' 7.5 st, me 11.5 st
Riding style: All for Leisure, to include cream tea stops etc...
Generally unassisted unless hills or wind. Normally, about 140 to 180 miles from a full 10A battery. Mrs 'O' gets more coz she's a lightweight! Normal overall average on rides ~10mph. Distances 30-40 miles in summer, 20-25 miles in winter. Never in the rain, we can get wet but not the bikes.

 

[flash]

A big factor is the weight of the rider. Light riders can cruise round on low power, so the stuff could last a very long time. Heavier riders will be pedalling harder and probably be using more motor power. The wear rate goes up exponentially with power through the chain.

One of the problems on this forum is that we often get statements of fact without the qualification that puts them in context. That's a real problem for noobs that take these facts at face value and base their decisions on them. I worry that people might be doomed to disappointment like this, which is the reason I'm often quick to challenge unqualified facts.

To answer your question on chain maintenace. I have a £7 chain on my bike from Ebay. It is branded, but I can't remember who's. It's done 2500 miles of moderately hard pedalling so far, and it isn't showing any signs of deterioration. I've never cleaned it, but I've lubricated it a few times. In the winter, I used White Lightening wet lube, which turned into valve grinding paste and gummed up my rear derailleur, so I wouldn't use it again. Now, each 500 miles, it gets a drizzle of hypoid 90 gear oil.

I'd have thought the hypoid 90 is a little thick for chains although it will probably not pick up too much grit..
When I used to do a big mileage each week, I had 2 chains and soaked one in diesel whilst using the other one. I would change the chains over each week. Using this system I would get thousands of miles out of the 2 chains.
Now I use a good quality 2 stroke oil, the sort designed to be injected into the engine not the chainsaw stuff. This seems to repel grit for some reason and I get good chain and gear train life. I discovered this by accident. I just happened to have 5 litres of the stuff and no 2 stroke engines and being a bit tight decided to use the stuff on my chain.

 

[kinega]

I have got KTM Macina Action. I weigh 85kg, ride to work everday & do a bit of off road riding at the weekend.
First chain snapped at 1510 miles after 7 months. Dealer considered this acceptable & I paid for a replacement. I argued that I was using bike for how it was intended but was told definitely not warranty.
Second chain snapped at 1649 miles on 23-10. Dealer repaired
Third chain snapped at 2227 miles 04-03. I replaced this one myself and is still on this chain, mileage now apx 2900 miles.
I am now critical of how the gearchange feels, like oriteroom.
I use 3-1 oil to lube & every couple of weeks I take the wheel out, strip the derailleur & clean all the cack out of this & the sprockets.
I am still concerned about chain life, I do try to look after the bike & keep it clean & lubed. It is sold as a premium quality mountain bike & should be able to cope better than this. It also seems to have an appetite for brake pads & tyres.

 

[mike killay]

I have only ever had one chain snap.
I am certain that it broke where I had joined the chain with a chain breaking tool. There was no sign of the rivet, it must have come out of both sides at once.
Which leads me to,
Should you ever use a chain breaking tool?
Shimano insist that their chains should be re-joined with the special long rivet.
Examination of SRAM chains shows that the ends of the rivets are peened over, perhaps that is why they supply their chain joining link, it was a SRAM chain that I broke, and I now suspect that these chains are not suitable for chain breaking tools.

 

[flecc]

it was a SRAM chain that I broke, and I now suspect that these chains are not suitable for chain breaking tools.

I have only used SRAM chains for over a decade now Mike, and use a chain breaker both for extending the new standard length where necessary and adjusting length. I've never had one break, only wear.

The only chain break I've had in more than two decades was the chain a Ridgeback bike came with new, back in 1996. That failed very early in life.
.

 

[mike killay]

I have only used SRAM chains for over a decade now Mike, and use a chain breaker both for extending the new standard length where necessary and adjusting length. I've never had one break, only wear.

The only chain break I've had in more than two decades was the chain a Ridgeback bike came with new, back in 1996. That failed very early in life.
.

It could be that the chain breaker itself is critical and it is necessary to ensure that the rivet is properly, fully pushed home evenly on both sides. I must confess that I did not check this point.

 

[EddiePJ]

It also seems to have an appetite for brake pads & tyres.

You can't blame the bike for that.

I also get through chains, brake pads and tyres at a rapid rate. The one and only cause being the rider.

I don't have a photo to show stretch, but this is a typical old and new chain.

As a chain related aside, it is always worth having at least one spare snap link attached via either a cable tie or key ring, to somewhere permanently on the bike. Obviously this is of no help if you don't also carry a pocket a chain splitter, but it could save the day if someone stops to help you.

 

[Tomtomato]

First chain snapped at 1510 miles after 7 months.
Second chain snapped at 1649 miles on 23-10.
Third chain snapped at 2227 miles 04-03.

Thanks for the informative post. You surely didn't get much mileage out of the first two chains!

From the other posts and the Woosh official advice, it sounds like replacing the chain after 1,200 - 1,500 miles would be a cautious measure.

 

[kinega]

I guess i am just shocked compared to a normal push bike. Spent virtually nothing on my old mountain bike, I know electric powered ones will have more wear & tear, but even so......

 

[Croxden]

I used wear out a lot of cotter pins in the olden days.

 

[Tomtomato]

Just found the official Kalkhoff advice (from their user manual):

========================
Maintenance of bike chains
Bike chains are wear parts. Bike chains with hub gears
wear out after roughly 3000 km, and after roughly
2000 km with derailleur gears.
=========================

2000 km = 1250 miles

 

[JohnCade]

Sounds about right. As said above it does depend on factors such as the weight of the rider, and the riding style and the terrain. If you don’t want to replace the cassettes and chainrings often then the use of a gauge, or other way of checking for chain wear will allow it to be changed before other more expensive parts of the drive chain wear out.

Some prefer to let it all wear out together, and that way you will get a lot more milage before it starts skipping. I tend to think it depends partly on how expensive the rest of it is, and whether you enjoy maintenance. But if it’s cheap and cheerful or you do then that can make sense. But if it has more expensive somewhat higher end parts I think it’s better and more cost effective and easier, to change the chain regularly before its deterioration wears the rest out prematurely.

 

[mike killay]

My main problem is the 11 tooth cog which hardly seems to last 50 miles.

 

[flecc]

My main problem is the 11 tooth cog which hardly seems to last 50 miles.

I agree, I dislike any rear sprocket under about 13 teeth, preferring to have a larger chainring. My currrent bike has a 60 tooth chainring so no need for tiny rear sprockets, 14 tooth my smallest.
.

 

[Deleted member 4366]

My main problem is the 11 tooth cog which hardly seems to last 50 miles.

Are you sure it's actually worn? The teeth are hooked when they're new.