New Chain Time?

NULevo

Well-known member
Nov 7, 2019
539
341
Nottingham
Hot on the heals of brake squeal, on my ride today, I started to hear an occasional clunk on the smallest 2 cogs, it feels like the chain skipping, but I can't be sure, as it doesn't happen when the bike is on the bike rack.

My understanding is that e-bike chains wear quicker than acoustic bikes due to the power and torque, understandable.

The bike's on 520 miles, so could it be the chain wearing? Is there any way of checking other than getting a chain checker? Happy to get one if necessary.

If I do need a new chain, what should I go for? It would need to either be cheap or last longer than the original KMC! I'm doing almost 100 miles a week at the moment, mainly on flat(ish) fire roads/tracks and country lanes, and don't fancy a new chain every 4-5 weeks. Thats before the new cassette and/or chainrings :(

Thanks guys :)
 

Utah Rider

Well-known member
Jul 4, 2019
147
189
Utah
Probably not the chain. Maybe bent derailleur hanger, or adjustment, or loose free hub/axle. A KMC will go 1200 miles or more. A SRAM will go much farther with fewer breaks.
 

Bones

E*POWAH Master
Subscriber
Apr 3, 2020
754
992
Harrogate
Just fitted a KMC so cant comment on chain life. Regarding Sram chains I am getting around 4/500 miles out of them before breaking or stretching to much. It all depends how much stick you give it.
1500 miles on the clock and on chain number 4
 

NULevo

Well-known member
Nov 7, 2019
539
341
Nottingham
Probably not the chain. Maybe bent derailleur hanger, or adjustment, or loose free hub/axle. A KMC will go 1200 miles or more. A SRAM will go much farther with fewer breaks.

Thanks, doubt its the hanger, it's not had any knocks. I'll have a go at adjusting the gear cable again, I did it a couple of weeks ago.
 

NULevo

Well-known member
Nov 7, 2019
539
341
Nottingham
Just fitted a KMC so cant comment on chain life. Regarding Sram chains I am getting around 4/500 miles out of them before breaking or stretching to much. It all depends how much stick you give it.
1500 miles on the clock and on chain number 4

Not given it much stick at all Bones, probably 150 odd miles in the wet/mud (cleaned and lubed after each ride), the rest since the good weather and lockdown.
 

Bones

E*POWAH Master
Subscriber
Apr 3, 2020
754
992
Harrogate
(y) Dont get to exited. Iv'e not had the gopro long and never done any editing either. Getting beter with experiance.:)
 

lumpy

🚁 CHOPPER 🚁
Nov 26, 2018
468
441
SF Bay Area
Hot on the heals of brake squeal, on my ride today, I started to hear an occasional clunk on the smallest 2 cogs, it feels like the chain skipping, but I can't be sure, as it doesn't happen when the bike is on the bike rack.

My understanding is that e-bike chains wear quicker than acoustic bikes due to the power and torque, understandable.

The bike's on 520 miles, so could it be the chain wearing? Is there any way of checking other than getting a chain checker? Happy to get one if necessary.

If I do need a new chain, what should I go for? It would need to either be cheap or last longer than the original KMC! I'm doing almost 100 miles a week at the moment, mainly on flat(ish) fire roads/tracks and country lanes, and don't fancy a new chain every 4-5 weeks. Thats before the new cassette and/or chainrings :(

Thanks guys :)


When to Replace a Worn Chain | Park Tool
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,429
8,671
Lincolnshire, UK
To check chain wear without a chain checker and assuming you don't have any vernier calipers, you only have one option left.

Remove the chain and measure it with a metal tape measure. Measure from pin to pin over 100 links. On a new chain that will measure 50". As a chain wears, it gets longer. So a chain that is worn by +0.75% which is the max wear for replacement, the chain will measure 50.375" which is 50-3/8. If it measures 1% the chain is "officially" scrap and will measure 50-1/2". Whatever measurement you get you can work out the %age yourself. But your measurement accuracy can easily be as good as +/- 1/32", which in percentage terms is +/- 0.0625%. This is accurate enough for most people.
 

NULevo

Well-known member
Nov 7, 2019
539
341
Nottingham
To check chain wear without a chain checker and assuming you don't have any vernier calipers, you only have one option left.

Remove the chain and measure it with a metal tape measure. Measure from pin to pin over 100 links. On a new chain that will measure 50". As a chain wears, it gets longer. So a chain that is worn by +0.75% which is the max wear for replacement, the chain will measure 50.375" which is 50-3/8. If it measures 1% the chain is "officially" scrap and will measure 50-1/2". Whatever measurement you get you can work out the %age yourself. But your measurement accuracy can easily be as good as +/- 1/32", which in percentage terms is +/- 0.0625%. This is accurate enough for most people.

Thanks Steve, I've ordered a chain checker tool, I figured I'm going to need one at some stage soon. Hopefully that might shed some light on whats going on.

I'll have a go at adjusting the gear cable tomorrow, in case its a problem there.

It did think it could be the 36t chainring, but thats been on for weeks and the issue only started yesterday.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,429
8,671
Lincolnshire, UK
.........

I'll have a go at adjusting the gear cable tomorrow, in case its a problem there.

It did think it could be the 36t chainring, but thats been on for weeks and the issue only started yesterday.

When washing the bike, it is easy to move the knurled wheel that adjusts cable tension. Or maybe some other change has happened, like one of the cable ferrules has shifted (reducing cable tension and causing your problem). Sometimes it's the passing foliage that does the evil work for you.

Assume that the simple things have gone wrong first and check them. They are usually easy and cheap to sort out.
 

NULevo

Well-known member
Nov 7, 2019
539
341
Nottingham
When washing the bike, it is easy to move the knurled wheel that adjusts cable tension. Or maybe some other change has happened, like one of the cable ferrules has shifted (reducing cable tension and causing your problem). Sometimes it's the passing foliage that does the evil work for you.

Assume that the simple things have gone wrong first and check them. They are usually easy and cheap to sort out.

I hope it is something simple, I'm going to start at the beginning with the cable and go from there until the checker arrives.
 

James_C

Active member
Nov 25, 2019
455
221
Kent, UK
check youtube for videos on SRAM cassettes clicking. Mine was driving me nuts. I fixed it in the end by carefully filing a couple of teeth on the bottom 2 cogs. You can revolve the chain backwards and find the clicky tooth that way. You might need to video it rotating slowly to see it if your eyesight isnt brilliant.
 

NULevo

Well-known member
Nov 7, 2019
539
341
Nottingham
check youtube for videos on SRAM cassettes clicking. Mine was driving me nuts. I fixed it in the end by carefully filing a couple of teeth on the bottom 2 cogs. You can revolve the chain backwards and find the clicky tooth that way. You might need to video it rotating slowly to see it if your eyesight isnt brilliant.

Thanks, I'll have a look
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,143
4,674
Weymouth
Her e is a usefull aside. The original KMC chain on my Levo Comp got to 0.75% after 250 miles. It still worked flawlessly though so it is now my spare. I changed it for a KMC Exra Light Hollow Pin. That chain has been maintained in the same way as the original and has done 350 miles and is only just marginally over 0.5%. That chain did all of last winter as well. So much for E MTB specialist chains!! The Extra Light is also a much smoother change.
 

Brooky

Member
Jul 29, 2018
11
6
UK
Same happen to me, found a plate had come away from the rivet on the chain, it clicked back into place but replaced the chain just in case, only done 3 rides
 

NULevo

Well-known member
Nov 7, 2019
539
341
Nottingham
Spent some time today cleaning and lubing the chain and adjusting the gear cable. Then the chain checker arrived and it's showing 0.5, so a new chain is on the cards.

I'll have a look at the KMC Extra Light Hollow Pin, Any other recommendations?

Also I counted it as a 114 link chain, should I go longer now I have a 36t chainring?
 

Bones

E*POWAH Master
Subscriber
Apr 3, 2020
754
992
Harrogate
Had the back wheel out today and given the cassette a good clean as it was jumping like mad. I got the jewlers loop out and dremeled the worn bits and it's working fine now.
 

NULevo

Well-known member
Nov 7, 2019
539
341
Nottingham
Had the back wheel out today and given the cassette a good clean as it was jumping like mad. I got the jewlers loop out and dremeled the worn bits and it's working fine now.

I wish I was that brave! I wouldn't know where to start.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,429
8,671
Lincolnshire, UK
I wish I was that brave! I wouldn't know where to start.
Take a look at this for a start. It's picture of a worn front ring sat in front of a new one. Each gear on a worn cassette will look similar but will have a lot of ledges and ramps to assist shifting. Just showing a front ring makes it clearer where the problems are.
granny1.JPG

There are two things to note:
First is the shark fin profile carved into the tooth faces of the grey ring. Compared to the convex profile of the black ring, the grey ring has a concave tooth profile. The grey ring is well worn. That curved profile can hook onto the chain and cause chainsuck. ie where the chain does not leave the ring on it's way to the back of the bike, but is "sucked" upwards to jam in the ring.
Second is to ask where has that material gone that has been removed from the tooth profile? Some will have floated off as dust or flakes. But as you can see a lot of it has been pushed into forming the burrs at the sides of the teeth, (both sides). Those burrs themselves can hook onto the chain side plates and cause chainsuck on the front ring and impair shifting on the cassette.

A jeweller's loupe or any magnifying glass will help you see more clearly, but with good lighting you shouldn't need one. It is the side burrs that may be usefully be filed off. It is quicker, easier and all round better to remove the cassette from the bike before attempting the filing job. But if you want to do it in situ, make sure that you catch the filings as you don't want them going onto your chain or sticking to the oily cassette. There is nothing you can do about the worn tooth profile.

in my opinion, if the ring/cassette has this level of wear, then it is knackered and needs replacing and probably the chain too! A new chain would probably not run with gears this worn. I would only consider filing off the burrs if I needed to ride before the new kit had been delivered. Don't get me wrong, filing off the burrs will help, but it is very much a stop gap. However, if your gears and chain are all knackered, then it will allow you to get a few more rides before you come unstuck.
 

Bones

E*POWAH Master
Subscriber
Apr 3, 2020
754
992
Harrogate
It was definitely a bodge on my behalf that seems to have worked.
Here was my predicament.
The kitchen tap went faulty and I mended it. So I saved around £60.
The cassette neaded replacing, again around £60.
But I ran out of beer.
The cassette got bodged and the brewdog order is on its way. ??
 
Last edited:

Cyclopath1000

Active member
Apr 26, 2019
310
125
Davis Ca
It's at least the chain that is worn out. It could also be some of the more used small cogs on the cassette. These 12 speed cassettes are the silliest things to have on e bikes vs the more sturdy 8 speed sram ex1 which I got 3000 km out of my chain and cassette. Would I have gotten more out of the cassette if I changed the chain every 1000km....probably!! Every aspect of the ex1 is beefier.
 

Feb 14, 2019
70
49
Tillicoultry
Hot on the heals of brake squeal, on my ride today, I started to hear an occasional clunk on the smallest 2 cogs, it feels like the chain skipping, but I can't be sure, as it doesn't happen when the bike is on the bike rack.

My understanding is that e-bike chains wear quicker than acoustic bikes due to the power and torque, understandable.

The bike's on 520 miles, so could it be the chain wearing? Is there any way of checking other than getting a chain checker? Happy to get one if necessary.

If I do need a new chain, what should I go for? It would need to either be cheap or last longer than the original KMC! I'm doing almost 100 miles a week at the moment, mainly on flat(ish) fire roads/tracks and country lanes, and don't fancy a new chain every 4-5 weeks. Thats before the new cassette and/or chainrings :(

Thanks guys :)
I strip sown and clean every Saturday, 300 miles max before I'm at 0.75 on the chain checker tool. Learned the hard way had to replace the cassette, front chain ring and chain after 609 miles. Get used to checking or it will cost you a fortune
 

NULevo

Well-known member
Nov 7, 2019
539
341
Nottingham

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