Chain replacement question

[lightning]

So, l fit a new chain on my Ebike and after about 400 miles it's showing 0.5 on the chain checker tool.

The wear indicator then stays at 0.5 and l can do another 2-300 miles before it just about exceeds 0.5, and even then its barely detectable and can depend on how clean/well oiled the chain is.

When should l be replacing the chain? When it gets to 0.5 or fractionally under 0.5 after 400 miles
Or when it gets to 0.5 or fractionally over 0.5 at around 600 miles.

When do you replace yours? With chains at £30 each and hard to get, l don't want to be throwing one away unnecessarily.

l do around 200 miles per month, and had to get my last SRAM chain from Germany as my LBS said no stock until next year.

 

[Gary]

I don't replace chains at all until the whole drivetrain is worn out on any of my bikes
Cassette wear on my Emtb is no worse than on my normal bikes. (1000s of miles)
A cassette, chain and chainring cost me less than £50 Altogether.
£30 on new chains every 8 weeks is mental.
And yes, if you're ditching them that soon you are throwing away perfectly good chains

 

[RustyIron]

I don't have concrete answers, but here's my experience with my X01 drivetrain.
My bike is two months old, and just turned over 400 miles. Chain elongation was at 80%, so I ordered a replacement chain. In the meantime I installed a chain with 50% wear that I had saved for emergency use. The used chain runs perfectly fine, so I'll let it go until it's at 70%-80%, then I'll replace it.

 

[lightning]

Replacing the chain ring, cassette and jockey wheels costs around £200 on my 12 speed transmission

That's if you can get the parts. l've got a spare cassette but had to get it from the USA

 

[Gary]

instead of infinitely fitting new chains every 2 month have you considered just rotating 3 chains? by the time you're ready to fit your 4th chain your cassette and chainring will have 1200miles of wear so part worn chains should match that wear better than a brand new chain anyway.
How many miles do you get from your cassette and chainring swapping chains every 400 miles anyway?

 

[lightning]

l don't know, l replaced the first chain at 750 miles and the second chain is still on at 1250 miles but it's now showing 0.5 on the chain checker.

 

[Mikerb]

l don't know, l replaced the first chain at 750 miles and the second chain is still on at 1250 miles but it's now showing 0.5 on the chain checker.

The chain is less important ( and costly) than the cassette so maximising the life of the cassette is the main priority. I change chain at 0.75 for the first 2 chains on that cassette and then try a 3rd chain. If it works OK I run the third until the signs of slip which is often beyond 0.75. Then change chain and cassette. If the 3rd chain on the original cassette does not work well I refit the second chain and run it until it starts to slip Then its time for a new chain and cassette.

 

[lightning]

On 12 speed it says you have to replace the chain at 0.5.
ls yours 12 speed? lf so l might try what you are doing.

 

[Mikerb]

I have both 11 speed ( GX) and 12 speed ( X01).............do the same on both. It is all a bout balancing the wear of both the chain and the cassette. A chain and cassette will both wear with use but a decent cassette will wear more slowly ( especially if it is mostly steel). A very worn chain will induce more wear on the cassette but in my opinion 0.5% is too little to do that. I have found a good cassette will continue to work well with 2 chain changes and sometimes 3. When a cassette is worn and the chain is also worn they can still work fine maybe with some B tension adjustment until the telltale signs that a new cassette is required. Those signs are usually slipping on the smallest cog or whichever cog(s) you tend to use the most. Because my riding is mostly gravity runs plus of course the ride back up I rarely use the extremes of my cassette so middle cogs get the most wear. If you ride a lot using the smallest cog(s) you will reach the replacement time quite a bit earlier since the small cogs have much less chain wrap.

 

[lightning]

Yes l can see that, and it is the case being an ebike that most of my time on the road is spent in 11 (second smallest gear) on the cassette

 

[Sander23]

Yes l can see that, and it is the case being an ebike that most of my time on the road is spent in 11 (second smallest gear) on the cassette

Then you might want to switch to a casette where you can change those cogs on its own.
In my experience it works great. I tend to use the smallest cogs to and they get worn pretty fast.
I'm on a 8 speed ex1 drivetrain and I've been doing around 1700 km/ chain ( with 0.5% wear) and cogset. I'm now at 3800 km with my 3th chain and cog set .

 

[Gary]

If you're using the bike on the road a lot consider swapping to a larger chainring (36 or 38t) and a closer ratio cassette.
This will give you more choice in the higher gears and spread the wear far more evenly through the smaller sprockets.
On my commuting wheelset I run a 10speed 11-25 cassette and 36t ring. There's not a hill on any road in the UK that's not low enough for.

12 speed really isn't needed on an Ebike and is decreasing your drivetrains lifespan increasing your running costs massively

 

[Jamze]

instead of infinitely fitting new chains every 2 month have you considered just rotating 3 chains? by the time you're ready to fit your 4th chain your cassette and chainring will have 1200miles of wear so part worn chains should match that wear better than a brand new chain anyway.
How many miles do you get from your cassette and chainring swapping chains every 400 miles anyway?

This is what I do. SRAM GX.

At 1,250 miles now and still less than 0.5% wear (just) with perfect shifting. I rotate the chain every 250 miles, so I should get to 1,750 miles with no issues at all. Might make it to 2,500 miles even.

 

[steve_sordy]

This is what I do. SRAM GX.

At 1,250 miles now and still less than 0.5% wear (just) with perfect shifting. I rotate the chain every 250 miles, so I should get to 1,750 miles with no issues at all. Might make it to 2,500 miles even.

Please elaborate on what you mean by "I rotate the chain every 250 miles". What exactly is it that you do?

 

[Jamze]

Please elaborate on what you mean by "I rotate the chain every 250 miles". What exactly is it that you do?

I start with a new drivetrain + 2 spare chains.

Every 250 miles chain comes off and goes in a bucket of degreaser overnight, fresh chain goes on. I do it every 250 miles so there's not too much of a gap between swaps.

Very quick to swap the chains, I also degrease the cassette and chainring when the chain is off. Seems to work for me.

You just need to find somewhere to hang the chains...

 

[lightning]

With my first chain l just sprayed it with motorcycle chain grease after every couple of rides and it lasted 750 miles.

With the second chain l de greased it regularly and oiled it with one of the expensive posh oils (Rock n Roll) that's supposed to clean and oil the chain better etc and the chain's on the wear limit at 400 miles

l think l will go back to the motorcycle chain spray, it's a lot cheaper as well, and much quicker to apply, although it a bit messy as the chain, cassette and other parts get black and sticky with the product.

Also rotating the chains as recommended above seems a great idea and l will give that a try.

 

[Jamze]

Yeah with the rotating chain approach, you just keep going until shifting performance is unacceptable. No point worrying about the wear limit as you know a new chain will never work anyway, so might as well get as many miles as you can. Although I do measure it so I know when to start looking for new bits.

 

[Tribey]

I don't replace chains at all until the whole drivetrain is worn out on any of my bikes
Cassette wear on my Emtb is no worse than on my normal bikes. (1000s of miles)
A cassette, chain and chainring cost me less than £50 Altogether.
£30 on new chains every 8 weeks is mental.
And yes, if you're ditching them that soon you are throwing away perfectly good chains

What components are you running Gary?

 

[Arseni]

I’m experiencing similar wear pattern as the topic starter. Got 0.25 wear real quick (~50km) an was scared. But that 0.25 is still same after 500km, so it looks like new chains somehow reach initial wear real quick on emtbs and then the process slows down.
Fyi: that is SLX 12speed cassette and Deore chain.


On my normal bike, I just rotate three chains every 2-3K km and will probably do same on emtb, except maybe rotate a bit more often.

 

[Timochka69]

I just measured my chain and the 0.5% indicator just barely went into the chain. Now about 1650-1700 km on the chain. I'll replace the chain during the weekend. I run 3 chains and always replace at 0.5%. Then I run all the chains to 0.75%. Then I run the chains in succession for maybe 500 km each, if needed. After that the drivetrain pretty much will be knackered. My previous SRAM NX Eagle drivetrain lasted for 5865 km. For the lulz I tried mounting a new chain and it was skipping teeth on 3 cogs. I probably could have ran the drivetrain with the old chains a bit longer, but I decided to replace all drivetrain in the spring when the dry season begun.

I found it surprising that the drivetrain was still shifting pretty well after that amount of use. I do lube and clean the drivetrain pretty often.

 

[1oldfart]

I use 9 and 10 S on my Ebikes, it saves money and useless shifting.

 

[Gary]

What components are you running Gary?

Zee FR rear mech.
Zee 10speed shifter
Deore and 105 10 speed cassettes (11-36 for mtb, 11-25 for commute via road and off road) .
10speed SRAM chain 1030
Chinese 36t 104bcd 4 bolt NW chainring

 

[lightning]

l've just fitted my third new chain at 1250
miles, and the cassette won't take it, 9, 10 and 11 are jumping under load.

l've refitted the old chain and will run it to 2,000 miles then replace the cassette and fit the new chain back on.

The front chain ring doesn't seem
to wear out so fast, on my regular MTB l used to go through an XT 11 speed cassette about every 2,000 miles but the first front chain ring lasted until 7,000 miles.
The second front chain ring is still good at 13,000 miles.

Fortunately front chain rings seem to be readily available for my ebike, should it turn out that l do need one.

 

[Mikehorti]

I have a Bosch Gen4 with 12s Eagle 10-52 cassette and 32t chainring. I replaced the chain around 400 miles and just over .5% wear. Chain slip then occurred under load in most gears and power settings. I tightened the B screw 1/2 a turn and the chain then only slipped under the extra power delivered in eMTB mode. Tightened the B screw a further 1/4-1/2 and the slipping has stopped in all power modes however minor indexing is now needed

 

[Timochka69]

I have a Bosch Gen4 with 12s Eagle 10-52 cassette and 32t chainring. I replaced the chain around 400 miles and just over .5% wear. Chain slip then occurred under load in most gears and power settings. I tightened the B screw 1/2 a turn and the chain then only slipped under the extra power delivered in eMTB mode. Tightened the B screw a further 1/4-1/2 and the slipping has stopped in all power modes however minor indexing is now needed

I have found that SRAM Eagle are a bit finicky about the B-screw adjustment.

 

[Tribey]

Sounds a bit like the new chain is not meshing with the worn cassette. Only solution is a new cassette.

 

[lightning]

l never thought to try adjusting the B tension though, l will give that a try, there's nothing to lose.

 

[KSL]

interesting how long some of you are getting on your chains. I had a chain snap on my non-ebike not long ago with only 100 miles on it - thankfully I was in the garge and not out riding. Could have maintained it better, but I'm now always conscious of loosing a chain when out riding.