Chain Life

[Mcharza]

I know of at least six different ways of getting the correct length of a chain. The one I use is as follows. Put the chain in the biggest gear on the front and the biggest gear on the back. Adjust the chain length until the rear mech arm is pointing forward at 45 degrees. Job almost done; there is another step.....

For those with single pivot suspension or a hardtail, then yes the job is done. For anyone else, you need to fully compress the rear suspension, as in a G out, the wheelbase may increase sufficiently to rip the mech off! So the chain needs to be a bit longer to allow for the extension. If you have air springs, then just let the air out and compress the bike. If you have coil, then you will need a heavy friend or two to assist.

If your chain is too long you will be at increased risk of the chain rattling on the chain stay, or coming off the front ring if you don't have some sort of chain device. Get your chain length right, and with the aid of a clutch mech and a narrow wide ring, then you should rarely if ever drop a chain.

That's the method I always use. Steps 1 and 2

 

[Gary]

The one I use is as follows. Put the chain in the biggest gear on the front and the biggest gear on the back. Adjust the chain length until the rear mech arm is pointing forward at 45 degrees. Job almost done; there is another step.....

For those with single pivot suspension or a hardtail, then yes the job is done. For anyone else, you need to fully compress the rear suspension, as in a G out, the wheelbase may increase sufficiently to rip the mech off! So the chain needs to be a bit longer to allow for the extension. If you have air springs, then just let the air out and compress the bike. If you have coil, then you will need a heavy friend or two to assist.

Sorry but this isn't correct at all.
Depending on where the main pivot is single pivot rear suspension designs can have massive chain growth.
wheelbase doesn't even have to increase for chain growth to occur.
your 45deg rule isn't exactly scientific either as you're not taking cassette size or mech cage length into account. With an optimally shortened chain the mech cage angle can be considerably less than 45deg. (especially on a hardtail)
Also
With a coil shock REMOVE the spring to cycle the rear through full travel. THEN apply force to compress the bottom out bumper on the shaft to reach full travel (and check for chain growth).

 

[steve_sordy]

Sorry but this isn't correct at all.
Depending on where the main pivot is single pivot rear suspension designs can have massive chain growth.
wheelbase doesn't even have to increase for chain growth to occur.
your 45deg rule isn't exactly scientific either as you're not taking cassette size or mech cage length into account. With an optimally shortened chain the mech cage angle can be considerably less than 45deg. (especially on a hardtail)
Also
With a coil shock REMOVE the spring to cycle the rear through full travel. THEN apply force to compress the bottom out bumper on the shaft to reach full travel (and check for chain growth).

What I wrote wasn't made up by me, I lifted it and the other five methods from various bike-oriented websites, magazines etc. I can no longer tell you where they came from. But the "Shimano method" one will be easy to find (one of the other five).

Your point about the location of the single pivot being important is correct and I will change the wording of the notes I have, I suspect that they were lifted from a source that was thinking about bikes with the pivot co-located or very close to the BB.

I am very interested in your statement "wheelbase doesn't even have to increase for chain growth to occur". I am not disagreeing with it, because I think can conceive of circumstances where that would happen, but I'm not sure. I really would be interested in how you see it happening. Once I understand that, I will change the wording on the notes I have, even if only to remove the reference to wheelbase.

I have never owned a bike with a coil shock, so the bit about using a heavy friend to assist was lifted from one of the sources I referred to. I made the fatal assumption that because it was coming from a bike mag and it was subsequently uncorrected by anybody, that it was authoritative. I am willing to accept your recco to remove the coil shock first, but I confess that I don't understand why it is necessary. If the bump stop can only be compressed with the coil removed, why is it even there? Clearly I am missing something and I would be grateful if you would enlighten me so that I can change my notes with understanding rather than just copying what you say in ignorance as I did before. I can see that if someone didn't have a heavy friend on hand then the only way to do it would be to remove the coil (same effect as letting the air out of an air shock).

I accept that leaving the mech pointing forward at 45 degrees is not entirely scientific, for the reasons that you outline. One link more or less or even half a link if you use a magic link, will move the angle. I agree that 45 degrees may not be the scientifically exact figure, but it can be very easily estimated because it's half way between horizontal and vertical. I know that it can be less depending upon the bike, because I've had it less on at least one of my bikes. I was trying to give guidance that was simple to use, and safe. I was not trying to produce a scientific report, with proof and references etc that would give the perfect solution for every bike out there. I suspect that if I had suggested that the angle be 42 degrees I would have attracted some derision for my use of precision.

I believe that the phrase "this isn't correct at all" is an overstatement implying that the whole of what I posted is incorrect. But I am always happy to learn - every day is a learning day.

 

[Gary]

What I wrote wasn't made up by me, I lifted it and the other five methods from various bike-oriented websites, magazines etc.

That's no excuse for repeating bad advice though. Many magazine journos talk utter pish. Randoms on the internet even more so.

Using a rule about derrailleur cage angle to determine optimum chain length isn't necessarily going to be even vaguely accurate for any set up other than your own personal one..
and telling folk not to bother compressing their suspension on a single pivot is a pricy mistake waiting to happen.

Sorry if this all sounds a little harsh. for background I've worked as a bike mechanic in shops, workshops, on the race circuit and teaching for almost 30 years now and fitted and set up many thousands of drivetrain combinations and am obviously just a little more 'black and white' with my definition of "correct" than you.
Yeah. I'm pedantic but the bottom line is I just don't want someone blindly following your advice and snapping their mech off.

 

[steve_sordy]

@Gary Fair enough. If I had thought it was bad advice, I would not have repeated it. It was an honest mistake and I stand corrected. Thank you.
I would appreciate the advice you give that would pass your tests.

 

[jxj]

Adding a tested fit result here for the Sram PC-1110 114 link chain. I installed this chain on a 2018 Turbo Levo Carbon Comp (Carbon front / AL rear triangle) size Large, with a stock rear 11-42 cassette and rear mech and a 36T N/W RaceFace chainring. Bottomed out the air shock and it takes every last millimeter of travel out of the rear mech in the 42 ring on the cassette but it doesn't bend or overstress the rear mech. One more tooth front or rear and this will not work for me. I doubt that I will ever fully compress the rear shock in the lowest gear but it is possible without damage. My factory chain was 116 links which worked fine with a bit of travel left in the rear mech on the 42 ring with both the factory 32T chainring and my upgraded 36T chainring. Have not ridden the PC-1110 chain yet but it shifts just fine in the shop.

 

[Maastricht]

Hi guys,

May I ask you for some advise?

I am riding the 2019 Levo Comp with the standard KMC X11ET chain and the SRAM PG-1130, 11-speed, 11-42t cassette. I was advised by my LBS to extend the driveline life by running two chains. So I ordered a 2nd KMC chain e11 EPT (EPT=anti corrosion coating).

After riding only about 300km in mostly eco, sometimes turbo and a few times turbo mode, I changed the original X11ET chain for the e11 EPT chain. However the result was that the new chain was already slipping over the two smallest gears as soon as you push the pedals hard. (also with the motor turned off) My LBS checked all fine adjustments of the derailleur everything should be fine but the new chain kept slipping over the two smallest gears. So in the end my LBS exchanged the new chain for the original chain again and the slipping was solved but in this way I seem not to be able anymore to extend the lifetime of the driveline.

I am curious if others recognize this issue and see this as normal wear of the cassette and the original chain. From @khorn for example I know he exchanges between several chains oftenly.

I read some while ago too that especially the standard KMC X11ET tends to stretch quickly. I don't have a chain measurement tool and my LBS said they normally don't use it either as these measurement tools are most indicating new chains too quickly.

Thanks for your support in advance!

 

[jxj]

Maastricht,

I think using a chain wear measurement gauge, tool or 6" caliper is essential. If your old chain is worn beyond 0.75 and you put a new chain on I have seen slipping when you then put a new chain on. The new chain doesn't ride correctly in the worn chainring and cassette sprockets.

I've found the best results by putting two or three chains in rotation with new chainring and cassette. Rotate them frequently and when each one reaches between 0.5 and 0.75 chain wear indicator on the tool I take that chain out of rotation and hang it on a hook in the shop.

Now what to do with these old chains, weld up some yard art?

 

[Frankieboy]

Maastricht,

I think using a chain wear measurement gauge, tool or 6" caliper is essential. If your old chain is worn beyond 0.75 and you put a new chain on I have seen slipping when you then put a new chain on. The new chain doesn't ride correctly in the worn chainring and cassette sprockets.

I've found the best results by putting two or three chains in rotation with new chainring and cassette. Rotate them frequently and when each one reaches between 0.5 and 0.75 chain wear indicator on the tool I take that chain out of rotation and hang it on a hook in the shop.

Now what to do with these old chains, weld up some yard art?

Chain art sound interesting, perhaps some crazy clockwork sculpture?

 

[Maastricht]

Maastricht,

I think using a chain wear measurement gauge, tool or 6" caliper is essential. If your old chain is worn beyond 0.75 and you put a new chain on I have seen slipping when you then put a new chain on. The new chain doesn't ride correctly in the worn chainring and cassette sprockets.

I've found the best results by putting two or three chains in rotation with new chainring and cassette. Rotate them frequently and when each one reaches between 0.5 and 0.75 chain wear indicator on the tool I take that chain out of rotation and hang it on a hook in the shop.

Now what to do with these old chains, weld up some yard art?

Hi jxj,

Thanks for your feedback!

A few more questions if you don't mind:
- When you rotate your chains frequently, would you say I wasn't quick enough by rotating the chain after only 300km's? The quick wear really suprises me but I was used to a normal mtb and no emtb.
- I can't find the original KMC X11ET chain on the KMC website. I read of other forum posts that this chain tends to stretch quickly. If this is true that that could have ruined my cassette so early. Do you agree?
- I do have a Mitutoyo caliper here at home. Do you maybe know the length which corresponds to 0.5 and 0.75 wear?

Thanks for your help!

 

[Paul Mac]

I have the same issue, and am wondering if it's a mistake to try and swap chains on an ebike to prolong the life of the cassette.
I also have a 2019 Levo, I changed the first chain at about 300 miles after my checker tool indicated that the chain was worn 0.5.
The next chain lasted about another 400 miles before it had stretched to 0.5, but on putting on my third new chain, I was experiencing chain slip on the last three cogs.
I have now put back on the old chain and it all runs sweet.
I am now going to run this until it starts to misbehave and then change the cassette, chain and chain ring together.
If I get loads more mileage out of this, I'll just do this every time rather than keep forking out for new chains.

 

[jxj]

Hard to say on the rotation. That doesn't seem like too many miles on the chain but every situation is different, the amount and type of dirt and slop that gets on your chain, the frequency and how you clean the chain and how you lube the chain all make a huge difference in chain life in my experience.

At 800 miles on my 2018 TL CC I rotated the chain at about 0.45%. I clean my chain and drivetrain frequently and try not to shift under load and I ride alot in the forest where the dirt isn't as bad as desert or other gritty places.

I usually use this as it is easy and quick:
CC-3.2 Chain Checker

When I use calipers this is how I do it.
1) set the caliper at about 5.6 in to slide it in the link openings.
2) insert the inside measuring jaws between the chain rollers.
3) extend the jaws to tension the chain and record the measurement
Measurements rounded up to the nearest 0.005"
new chain = 5.715"
0.5 = 1/2% stretch/wear = 5.745"
0.75 = 3/4% stretch/wear = 5.760"
1.0 = 1% stretch/wear = 5.775"

 

[Maastricht]

Hard to say on the rotation. That doesn't seem like too many miles on the chain but every situation is different, the amount and type of dirt and slop that gets on your chain, the frequency and how you clean the chain and how you lube the chain all make a huge difference in chain life in my experience.

At 800 miles on my 2018 TL CC I rotated the chain at about 0.45%. I clean my chain and drivetrain frequently and try not to shift under load and I ride alot in the forest where the dirt isn't as bad as desert or other gritty places.

I usually use this as it is easy and quick:
CC-3.2 Chain Checker

When I use calipers this is how I do it.
1) set the caliper at about 5.6 in to slide it in the link openings.
2) insert the inside measuring jaws between the chain rollers.
3) extend the jaws to tension the chain and record the measurement
Measurements rounded up to the nearest 0.005"
new chain = 5.715"
0.5 = 1/2% stretch/wear = 5.745"
0.75 = 3/4% stretch/wear = 5.760"
1.0 = 1% stretch/wear = 5.775"

Thanks for your feedback again!

I will measure the original chain tomorrow and will post the results here on the forum.

Like you I always clean my bike after each ride. I also try not to shift under load. I must admit that it has been very muddy here in The Netherlands but still I am surprised that after an average of about 10 rides the cassette is already that damaged the a new chain slips over the teeth. Especially as it slips over the two smallest gears. Mostly I drive on the smallest gear or maybe the bigger gears but not for my feeling I hardly ride on the second gear. I keep finding it strange but I am really happy with your help.

 

[jxj]

Two things give me the greatest issues on my prior Shimano MTB. Mud and granite dust here in the California Sierra and in Utah are very abrasive.

This is my first Sram bike. All my other road bikes and MTB for the last 20 years have been Shimano. I don't have enough miles to know if this may be a Sram issue? Perhaps some with more drivetrain cycles on the Sram drive system can help us with this?

 

[Macone]

My Focus came with a HG54 Shimano 10 spd chain and I got about 1400kms out of it before stretch past .75, my LBS didn't have one in stock and fitted a CN6600 Ultegra chain. 300km later and its already at .75. HG54 on order now of course

 

[Maastricht]

My Focus came with a HG54 Shimano 10 spd chain and I got about 1400kms out of it before stretch past .75, my LBS didn't have one in stock and fitted a CN6600 Ultegra chain. 300km later and its already at .75. HG54 on order now of course

Thanks! I am not 100% sure but can the reason of the high wear on the CN6600 Ultegra chain be related to the fact that it isn't designed for ebike usage?

 

[Maastricht]

Hard to say on the rotation. That doesn't seem like too many miles on the chain but every situation is different, the amount and type of dirt and slop that gets on your chain, the frequency and how you clean the chain and how you lube the chain all make a huge difference in chain life in my experience.

At 800 miles on my 2018 TL CC I rotated the chain at about 0.45%. I clean my chain and drivetrain frequently and try not to shift under load and I ride alot in the forest where the dirt isn't as bad as desert or other gritty places.

I usually use this as it is easy and quick:
CC-3.2 Chain Checker

When I use calipers this is how I do it.
1) set the caliper at about 5.6 in to slide it in the link openings.
2) insert the inside measuring jaws between the chain rollers.
3) extend the jaws to tension the chain and record the measurement
Measurements rounded up to the nearest 0.005"
new chain = 5.715"
0.5 = 1/2% stretch/wear = 5.745"
0.75 = 3/4% stretch/wear = 5.760"
1.0 = 1% stretch/wear = 5.775"

Hi jxj,

Yesterday I ordered the chain checker which you advised. We can order until 23:00 local time. I ordered it just in time 22:50 and will receive it this morning. I will let the results know.

 

[Mcharza]

Hi jxj,

Yesterday I ordered the chain checker which you advised. We can order until 23:00 local time. I ordered it just in time 22:50 and will receive it this morning. I will let the results know.

You have very good and fast delivery system

 

[Mcharza]

In my 30 year MTB career, I have learn something. You need to change chains and cassette at the same time, unless you use a twin chain rotation

 

[Maastricht]

You have very good and fast delivery system

I am aware yes, I guess it's the advantage of The Netherlands being such a tiny country where we have excellent logistics.

 

[Maastricht]

In my 30 year MTB career, I have learn something. You need to change chains and cassette at the same time, unless you use a twin chain rotation

Thanks and yes, that's exactly the reason why I wanted to start with the twin chain rotation.

 

[Maastricht]

Hard to say on the rotation. That doesn't seem like too many miles on the chain but every situation is different, the amount and type of dirt and slop that gets on your chain, the frequency and how you clean the chain and how you lube the chain all make a huge difference in chain life in my experience.

At 800 miles on my 2018 TL CC I rotated the chain at about 0.45%. I clean my chain and drivetrain frequently and try not to shift under load and I ride alot in the forest where the dirt isn't as bad as desert or other gritty places.

I usually use this as it is easy and quick:
CC-3.2 Chain Checker

When I use calipers this is how I do it.
1) set the caliper at about 5.6 in to slide it in the link openings.
2) insert the inside measuring jaws between the chain rollers.
3) extend the jaws to tension the chain and record the measurement
Measurements rounded up to the nearest 0.005"
new chain = 5.715"
0.5 = 1/2% stretch/wear = 5.745"
0.75 = 3/4% stretch/wear = 5.760"
1.0 = 1% stretch/wear = 5.775"

Hi jxj,

I just received the chain checker and the 0.75 side falls at some places easily in the chain and at a few places with a very gently push.

I also checked the chain with the Mitutoyo caliper.

You mentioned:
new chain = 5.715"= 145,16mm
0.5 = 1/2% stretch/wear = 5.745"= 145,92mm
0.75 = 3/4% stretch/wear = 5.760"= 146,30mm
1.0 = 1% stretch/wear = 5.775"= 146,69mm

At most places I measure between 0.75 and 1.0% wear. I remember someone earlier mentioned that the original KMC chain that comes with the Levo is not that good. I will try to find that post back again. I understand wear will happen and I also understand riding an emtb will require more service but still I am asthonished that a chain wears out after only 300km where I mostly rode in eco. The result is that the cassette is now worn too so two chain rotation isn't possible anymore.

Are there other riders here on the forum which can share their experiences? For me it feels that the original Levo Comp 2019 KMC X11ET chain (which I can't find on the KMC website either) is not fit for purpose if it wears out this quick.

Edit: I found the earlier post of @brizi2003: Specialized Kenevo Chain Wear - EMTB Forums
where he reported some extreme wear too. Can you maybe update us on your current situation?

 

[Thomas]

In my 30 year MTB career, I have learn something. You need to change chains and cassette at the same time, unless you use a twin chain rotation

And if You have 250-400 EUR cassette?

 

[Mcharza]

And if You have 250-400 EUR cassette?

Haha, true. That's why I prefer to use Shimano

 

[Thomas]

We will see.
Was wondering, how an average 6-12% road or fire-road climbs effect chain ware, compare to the proper trail climbs? I can see after 500km and 5K Elev Gain on a road, there is no problem regarding this, still plenty life left in stock KMC chain.
I forced myself to basically stop pedaling for a second when pushing hard, especially when upshifting on a climb. Thankfully the motor doesn't disengage in that split second, so the bike still have a little momentum and gives you right amount of time to shift without houlting to a stall or putt additional stress on the chan.

 

[Paul Mac]

And if You have 250-400 EUR cassette?

It's pointless buying the expensive cassettes for an ebike, your only paying for light weight.
You can get an 11 sp sram cassette for £80 suitable for an xd drive, and I bet you wouldn't tell the difference between that and a £250 xx1 cassette.

 

[khorn]

It sounds like an extremely short lifespan, especially when it’s not been under heavy abuse. I still have the stock KMC chain on my Levo being rotated with a cheap Shimano chain and it is not even at 0.5 after more than 700 km. Something must have been wrong from the very beginning.

Karsten

 

[hbakken]

It seems that most people in this thread change chain at 0.75% wear. I've changed at 0,5% after I started with 11 (and 12) gears, since I read somewhere that this would make you get much more miles out of the cassette.

I'm I wrong? Should I change a 0,75% or 0,5%???
My eKMC falls easily into 0,5% after around 400km...

 

[Paul Mac]

It seems that most people in this thread change chain at 0.75% wear. I've changed at 0,5% after I started with 11 (and 12) gears, since I read somewhere that this would make you get much more miles out of the cassette.

I'm I wrong? Should I change a 0,75% or 0,5%???
My eKMC falls easily into 0,5% after around 400km...

No you are right, they do say 0.5 for 11 and 12 speed cassettes, but on an ebike, you will be changing the chain very frequently when changed at 0.5.

 

[jxj]

I agree that expensive lightweight cassettes are not that important on a bike this heavy, we need strong not light in this component.

I see Sunrace makes 11sp cassettes that should work on at least my version of the Levo. I'm off to search if anyone has run them successfully.

I wonder if we would be better off with 10x1 setup on these bikes? More robust chain and gears. I wouldn't miss the gear as long as I could keep at least 10-42, what is in between doesn't matter as much to me on ebikes.