Cassette Chain Wear

[Stuart569]

Yesterday my chain started slipping on the smallest cog at the back. I hadn't even checked for chain wear as I've only done 320 miles from new. Forgive my ignorance but is this not a bit premature? It's my first E-bike so very little experience. I would of expected some accelerated wear due to extra load from motor but not this much. The chain is 3/8" out over 48 inches so .78% also confirmed with park chain wear checker. Do I need to change my front chainring as well as rear cassette and chain?

 

[Gary]

the chainring will show wear visibly. simply look at the teeth. The curves between each tooth should be perfectly symetrical. any obvious wear on the leading edge of a tooth will be obvious if looked at closely.
Being Narow wide any amount of wear reduced the rings chain retention ability.

Good quality alu NW rings are available from Ebay (chinese sellers) for under a tenner if your motor takes standard 4 bolt 104bcd fitment

340miles is extremely low mileage to have worn out your cassette and chain IMO. What accelerates wear most are poor drivetrain maintenance and poor shifitng (under load). always ease off the pedals just before shifting and you'll reduce wear rate hugely. And always clean/wipe down chain after rides, especially if ridden in wet/muddy conditions. Thoroughly clean the drivetrain if needed and always re-lube your chain when required. Being just as careful not to overlube (it just attracts more shite to stick to the chain/cassette/jockeys/rings). Once in a while also check your jockey wheels for gunk and remove it. UK road riding in wet conditions is terrible for creating a horrible paste on jockey wheels. this is not good for your chain.
hope some of this helps.

Ps. also stick to Shimano/Sram for your cassettes. Sunrace/Box cassettes have terrible durability and dodgy sprocket design making shifting/running noticably less smooth.

If you're getting through cassettes/chains really fast consider swapping to Shimano 10 speed drivetrain. it'll cost you a fortune otherwise. 10 speed Shimano Deore is really cheap and MORE durable than the 11 or 12 speed offerings from Shimano or SRAM. Good quality, still has the clutch feature and works flawlessly. The only downside is range as an 11-42 is the widest range 10 speed shimano cassette available. (losing ONE lower gear shouldn't be a problem on an Ebike really. I could happily run 11-36 on my Ebike with a 36t ring)

 

[Stuart569]

the chainring will show wear visibly. simply look at the teeth. The curves between each tooth should be perfectly symetrical. any obvious wear on the leading edge of a tooth will be obvious if looked at closely.
Being Narow wide any amount of wear reduced the rings chain retention ability.

Good quality alu NW rings are available from Ebay (chinese sellers) for under a tenner if your motor takes standard 4 bolt 104bcd fitment

340miles is extremely low mileage to have worn out your cassette and chain IMO. What accelerates wear most are poor drivetrain maintenance and poor shifitng (under load). always ease off the pedals just before shifting and you'll reduce wear rate hugely. And always clean/wipe down chain after rides, especially if ridden in wet/muddy conditions. Thoroughly clean the drivetrain if needed and always re-lube your chain when required. Being just as careful not to overlube (it just attracts more shite to stick to the chain/cassette/jockeys/rings). Once in a while also check your jockey wheels for gunk and remove it. UK road riding in wet conditions is terrible for creating a horrible paste on jockey wheels. this is not good for your chain.
hope some of this helps.

Ps. also stick to Shimano/Sram for your cassettes. Sunrace/Box cassettes have terrible durability and dodgy sprocket design making shifting/running noticably less smooth.

If you're getting through cassettes/chains really fast consider swapping to Shimano 10 speed drivetrain. it'll cost you a fortune otherwise. 10 speed Shimano Deore is really cheap and MORE durable than the 11 or 12 speed offerings from Shimano or SRAM. Good quality, still has the clutch feature and works flawlessly. The only downside is range as an 11-42 is the widest range 10 speed shimano cassette available. (losing ONE lower gear shouldn't be a problem on an Ebike really. I could happily run 11-36 on my Ebike with a 36t ring)

Thanks for the good info. Yeah the bottom 2 cogs look pretty chewed up. I probably don't look after the drive train as well as I should although I do lift off when changing gears. I was going to upgrade to 11-46 XT as it's SLX 11-48 that's on the '19 E-Sommet VR. It's only a few quid more for 2 less teeth. Do you think it's worth it or should I just go with the 11-40 SLX for 32 quid and save myself 28? I never use the big cog at the back so won't miss it. I was also going to go for the XT chain, again do you think it's worth it or should I just go cheap and cheerful and accept the 59 quid hit every 300 miles (more hopefully with better maintenance). I guess the main question is how much better is XT over SLX for wear?

 

[Gary]

I use 11-40 SLX
bonus is it only has the ONE Alu sprocket
XT isn't any more durable at all
SRAM PC1130 cheap (regularly discounted) and durable

 

[Stuart569]

the chainring will show wear visibly. simply look at the teeth. The curves between each tooth should be perfectly symetrical. any obvious wear on the leading edge of a tooth will be obvious if looked at closely.
Being Narow wide any amount of wear reduced the rings chain retention ability.

Good quality alu NW rings are available from Ebay (chinese sellers) for under a tenner if your motor takes standard 4 bolt 104bcd fitment

I've currently got a 34t up front but I feel the bike lacks a bit at top end. Could I squeeze a 38t in at the front? Pic below. Looks tight.

 

[Stuart569]

I use 11-40 SLX
bonus is it only has the ONE Alu sprocket
XT isn't any more durable at all
SRAM PC1130 cheap (regularly discounted) and durable

Right spot on. 11-40 and the Sram chain it is.

 

[steve_sordy]

I ride in mostly sandy conditions and my Shimano 11 speed chain (dunno which one) has done almost 860 miles and is less than half worn. The chain and cassette also look fine. I weigh 14.5 stone (203lbs) in my riding gear, I shift with mechanical sympathy and I wipe down and lube the chain before every ride.
You may have been unlucky, but if you never clean or lube the chain, then it won't last long. If your chain and cassette is that bad then the ring may also be affected and may not run with a new chain.

I have attached some pics of worn teeth compared to new ones so that you can see what to look for.

 

[Stuart569]

I ride in mostly sandy conditions and my Shimano 11 speed chain (dunno which one) has done almost 860 miles and is less than half worn. The chain and cassette also look fine. I weigh 14.5 stone (203lbs) in my riding gear, I shift with mechanical sympathy and I wipe down and lube the chain before every ride.
You may have been unlucky, but if you never clean or lube the chain, then it won't last long. If your chain and cassette is that bad then the ring may also be affected and may not run with a new chain.

I have attached some pics of worn teeth compared to new ones so that you can see what to look for.
View attachment 19148

View attachment 19149

Thanks Steve. The front looks fine. I'll be sure to look after the drivetrain a bit better but I fear it's the abuse I give it on the trails that's causing it. I use the top 2 gears coming down my local trails 99% of the time and have assistance between 130% and 300%. I should probably shift down a couple gears or use less assistance more than I do but that costs time so I leave the motor to do the work and just go hell for leather but that's how I enjoy riding. It's not a huge hit to take every few hundred miles. Worth every penny?

 

[Gary]

38t will fit but its so close to the swing arm that any play in the main pivot or crank axle (thus WILL happen) and you risk mullering the chainstay. So NO. I'd stick to a 36t. In the 11t sprocket it's good for 40mph if you can spin decently fast.

 

[Gary]

Learning to spin faster and fitting a 36t ring should keep you out of the 11 a d 13t sprockets more.
My most used gear descending is actually 36x15 as its just right for that one pedal stroke accelerating out of corners. My local descents are technical national/international DH and Enduro tracks though. Flat out descending spinning up fast and then freewheeling /tucking and resfing/pumping the terrain is almost always fastest. Over pedalling.

Ideally emtb cassettes should be very close ratio (ie one tooth jump) from 11t to 15. Then 17, 19 before larger jumps to a max of 42t.
All the Emtb specific cassettes on the market are shit. No more durable and with fucking stupid ratios.

 

[Stuart569]

Learning to spin faster and fitting a 36t ring should keep you out of the 11 a d 13t sprockets more.
My most used gear descending is actually 36x15 as its just right for that one pedal stroke accelerating out of corners. My local descents are technical national/international DH and Enduro tracks though. Flat out descending spinning up fast and then freewheeling /tucking and resfing/pumping the terrain is almost always fastest. Over pedalling.

Ideally emtb cassettes should be very close ratio (ie one tooth jump) from 11t to 15. Then 17, 19 before larger jumps to a max of 42t.
All the Emtb specific cassettes on the market are shit. No more durable and with fucking stupid ratios.

Right I'll look in to a 36t front ring. Again thanks for the good info. The cost of a new cassette and chain every 300 miles will also encourage me to learn to spin faster and use a lower gear I'm sure?.

You're lucky having all them trails on your doorstep. Had to travel 2.5 hours yesterday for a blast at Aonach Mòr . Never again on the e-bike though?.

 

[Gary]

No worries man.
I'm in the middle of East Lothian so my out the door trails are fairly flat. Loads of singletrack and one decent DH/play area. or the fairly dull tracks in the Lammermuir hills but Golfie/Inners/GT/Peebles/Yair/Thornielee etc are just 35-40mins drive away.

Why was Aanoch mor so bad on the E-bike?
Did you ride the DH track, Top chief, XC trails or the natural stuff surrounding?
I've ridden the DH track since 1995 (before it was lift accessed) so have ridden there on everything from a hardtail to shitty 90s DH bikes to modern DH bikes, slopestyle bikes and Enduro bikes.
The shorter the travel the more harsh the track becomes but I'm still happy smashing out 6+ runs no matter what bike I'm on.
I reckon Top chief would be ace on the E-sommet

 

[Stuart569]

No worries man.
I'm in the middle of East Lothian so my out the door trails are fairly flat. Loads of singletrack and one decent DH/play area. or the fairly dull tracks in the Lammermuir hills but Golfie/Inners/GT/Peebles/Yair/Thornielee etc are just 35-40mins drive away.

Why was Aanoch mor so bad on the E-bike?
Did you ride the DH track, Top chief, XC trails or the natural stuff surrounding?
I've ridden the DH track since 1995 (before it was lift accessed) so have ridden there on everything from a hardtail to shitty 90s DH bikes to modern DH bikes, slopestyle bikes and Enduro bikes.
The shorter the travel the more harsh the track becomes but I'm still happy smashing out 6+ runs no matter what bike I'm on.
I reckon Top chief would be ace on the E-sommet

It wasn't bad. I had a fucking amazing day. I just wouldn't do it again on the E-Sommet. Got there at just before mid day as had to drop the kids to school before I set off. Top chief was very good. First run was nice, the sun was out and I got the chance to take it all in. The weather changed quickly though and the second run down the back wasn't fun with the wind so tackled the DH trail a couple times. That was a fucking mission but fun too!! Would like to go back on a nice day but would rather it was on a V10 29er?.

 

[Gary]

Yeah. Best tool for the job right enough!

I still have 2 proper DH bikes. Not that either get that much use now.

 

[andykent]

It may well be you dont need to replace the whole cassette, just the 2 small sprockets that it slips in.

Shimano Sprocket for XT CS-M8000 11-speed

With a new chain it should all work again and works out quite cheap. 10 speed chain should be changed at .75 wear, a 11 or 12 speed chain, around the 0.5 mark.

 

[steve_sordy]

It may well be you dont need to replace the whole cassette, just the 2 small sprockets that it slips in.

Shimano Sprocket for XT CS-M8000 11-speed

Great find!

 

[Stuart569]

It may well be you dont need to replace the whole cassette, just the 2 small sprockets that it slips in.

Shimano Sprocket for XT CS-M8000 11-speed

With a new chain it should all work again and works out quite cheap. 10 speed chain should be changed at .75 wear, a 11 or 12 speed chain, around the 0.5 mark.

Interesting... Didn't realise you could buy individual sprockets. Thanks! I'll buy an 11 and 13 and fit them to the original cassette as a spare. I've already ordered a spare chain.

 

[Stuart569]

It appears the M7000 is interchangeable with the M8000 from 11t - 19t sprockets. I can't seem to find M700 sprockets so good to know.

Edit: It's the exact same sprockets used on the 11-19t on the SLX as the XT hence why they are interchangeable. It proves Gary's point about it not being worth spending the extra dough on the XT.

 

[Jamy]

38t will fit but its so close to the swing arm that any play in the main pivot or crank axle (thus WILL happen) and you risk mullering the chainstay. So NO. I'd stick to a 36t. In the 11t sprocket it's good for 40mph if you can spin decently fast.

40mph!!!!
36t front chainring with a 11t sprocket. your cadence would need to be 120rpm (which is the max my bosch gen 4 will take) and have 5inch wide tyres on

Bicycle Gear Speed Table | BikeCalc

Calculate cycling speeds in kilometers or miles per hour given cadence, chainring, sprocket, tire and wheel sizes.

www.bikecalc.com

 

[Stuart569]

40mph!!!!
36t front chainring with a 11t sprocket. your cadence would need to be 120rpm (which is the max my bosch gen 4 will take) and have 5inch wide tyres on

Bicycle Gear Speed Table | BikeCalc

Calculate cycling speeds in kilometers or miles per hour given cadence, chainring, sprocket, tire and wheel sizes.

www.bikecalc.com

That's nothing. @Gary can do it whilst sitting on the handlebars going backwards

 

[focusman]

I have a Focus Jam 2 and I am already on my third (yes 3rd) Cassette and chain in only 700 miles. Running a full Deore set up, light use and not a heavy chap either. I have been riding MTB since 1994 and I had NEVER needed to replace a cassette until this new fangled emtb came along!
I always used XT M737/M739 etc with zero issues.

 

[Gary]

Hopefully you've actually read through the 2+yr old thread you've just posted in?

You don't say what Deore drivetrain you're running. Deore is now available in 10, 11 and 12 speed configurations. 10 speed is the most cost effective and durable option of the 3 by far and the 12 speed microspline option the least durable/cost effective by far.
any cassette with a 10t smallest sprocket and 51t large sprocket is just asking for trouble as chain wrap in the smaller sprockets is already reduced massively from the rear mech's top jockey wheel needing more clearance (B-tension) in order for the mech to shift to the larger sprockets. when in a 10t sprocket (top gear) the chain only ever contacts 4 sprockets at a time. Under Ebike loads that's just a recipe for disaster and will cause the chain to slip under load even before the chain is worn to 0.75.

This thread is old. for a few years now I have been running 10 speed deore 11-36 cassette, SRAM 1130 chain and a 36t chinese NW chainring ring. This also allows me to run a Zee short cage rear mech and run the top jocket wheel much closer to the saccette sprockets increasing chain wrap greatly and I get over 4000miles from a single cassette/chain and chainring. (around £55-60 for the lot)
The 11 speed SLX 11-40, and 1130 chain with an XT medium cage rear mech I was using when this thread started used to get me somewhere around 2500-3000miles.

I just bin and replace the cassette, chain and chainring when it starts to slip in the smallest sprockets. Chain wear is off the scale well before that point.
jockey wheels generally last a few drivetrain replacements before showing wear

To be wearing out shimano cassettes to the point of slipping in just 230miles you're probably either running too much b-tension (which greatly reduces chainwrap in the smallest sprockets), shifting a lot less smoothly than you think is required, shifting under load, not looking after the drivetrain components all that well, riding in really harsh conditions, or using the smaller sprockets a lot more than you ever did with your mtbs. All of which increase drivetrain wear and being new to Emtb you're more than likely guilty of combination of a few these things TBH.

 

[pampmyride]

12 speeders? the loose sprox are available for Shimano 12 speed. But no stock in Europe it seems. I got some from China/aliexpress to rejuvenate the 1600 mile cassette which started slipping when a new chain was fitted. Not much wear show on the small sprox, but it was enough to give the odd click & slip...

 

[focusman]

Hopefully you've actually read through the 2+yr old thread you've just posted in?

You don't say what Deore drivetrain you're running. Deore is now available in 10, 11 and 12 speed configurations. 10 speed is the most cost effective and durable option of the 3 by far and the 12 speed microspline option the least durable/cost effective by far.
any cassette with a 10t smallest sprocket and 51t large sprocket is just asking for trouble as chain wrap in the smaller sprockets is already reduced massively from the rear mech's top jockey wheel needing more clearance (B-tension) in order for the mech to shift to the larger sprockets. when in a 10t sprocket (top gear) the chain only ever contacts 4 sprockets at a time. Under Ebike loads that's just a recipe for disaster and will cause the chain to slip under load even before the chain is worn to 0.75.

This thread is old. for a few years now I have been running 10 speed deore 11-36 cassette, SRAM 1130 chain and a 36t chinese NW chainring ring. This also allows me to run a Zee short cage rear mech and run the top jocket wheel much closer to the saccette sprockets increasing chain wrap greatly and I get over 4000miles from a single cassette/chain and chainring. (around £55-60 for the lot)
The 11 speed SLX 11-40, and 1130 chain with an XT medium cage rear mech I was using when this thread started used to get me somewhere around 2500-3000miles.

I just bin and replace the cassette, chain and chainring when it starts to slip in the smallest sprockets. Chain wear is off the scale well before that point.
jockey wheels generally last a few drivetrain replacements before showing wear

To be wearing out shimano cassettes to the point of slipping in just 230miles you're probably either running too much b-tension (which greatly reduces chainwrap in the smallest sprockets), shifting a lot less smoothly than you think is required, shifting under load, not looking after the drivetrain components all that well, riding in really harsh conditions, or using the smaller sprockets a lot more than you ever did with your mtbs. All of which increase drivetrain wear and being new to Emtb you're more than likely guilty of combination of a few these things TBH.

Thanks for taking the time to reply, I have indeed read the full thread and it certainly opened my eyes to a few things.
I am running a full Deore groupset, M4100 11-42 10 speed cassette with HG54 Chain. I never seem to use half of the cassette, just stay in the lower sprockets. The teeth on these are badly mashed even with such low miles of them. The front chainring is a 34t standard E8000 Shimano Item. I have only this week ordered a new chain and cassette of the same flavour! I do maintain my bike very well, a full wash and dry down after every ride the chain gets a proper clean and then lubed with a quality wet lube in winter and dry in summer.
I may look into the b-tension issue first.

 

[focusman]

Hopefully you've actually read through the 2+yr old thread you've just posted in?

You don't say what Deore drivetrain you're running. Deore is now available in 10, 11 and 12 speed configurations. 10 speed is the most cost effective and durable option of the 3 by far and the 12 speed microspline option the least durable/cost effective by far.
any cassette with a 10t smallest sprocket and 51t large sprocket is just asking for trouble as chain wrap in the smaller sprockets is already reduced massively from the rear mech's top jockey wheel needing more clearance (B-tension) in order for the mech to shift to the larger sprockets. when in a 10t sprocket (top gear) the chain only ever contacts 4 sprockets at a time. Under Ebike loads that's just a recipe for disaster and will cause the chain to slip under load even before the chain is worn to 0.75.

This thread is old. for a few years now I have been running 10 speed deore 11-36 cassette, SRAM 1130 chain and a 36t chinese NW chainring ring. This also allows me to run a Zee short cage rear mech and run the top jocket wheel much closer to the saccette sprockets increasing chain wrap greatly and I get over 4000miles from a single cassette/chain and chainring. (around £55-60 for the lot)
The 11 speed SLX 11-40, and 1130 chain with an XT medium cage rear mech I was using when this thread started used to get me somewhere around 2500-3000miles.

I just bin and replace the cassette, chain and chainring when it starts to slip in the smallest sprockets. Chain wear is off the scale well before that point.
jockey wheels generally last a few drivetrain replacements before showing wear

To be wearing out shimano cassettes to the point of slipping in just 230miles you're probably either running too much b-tension (which greatly reduces chainwrap in the smallest sprockets), shifting a lot less smoothly than you think is required, shifting under load, not looking after the drivetrain components all that well, riding in really harsh conditions, or using the smaller sprockets a lot more than you ever did with your mtbs. All of which increase drivetrain wear and being new to Emtb you're more than likely guilty of combination of a few these things TBH.

Well Gary, your hunch was correct, the B-tension was way out, the chain was almost being fed through the rear mech and onto the cassette vertically with virtually no chain wrap!! Now adjusted and the chain feeds from the mech horizontally following the line of the seat stay.

 

[Gary]

Change your chainring when changing cassette and chain.
Any wear on your chainring will accelerate the wear on your new chain.
Any 104 bolt NW chainring will fit.
Various Chinese ones from Ebay are good and around £8 or £9 a pop
Fit a larger 36t chainring and you'll use the smallest sprockets less.

 

[Gary]

oh... And now you've wound in B tension. The extra chain wrap should mean your old cassettes and chains (if you havent binned them) still have life left in them.
Chain length makes a difference to where the top jockey wheel sits in the smallest sprockets too and can increase/decrease both chain wrap and chain tension. Just be careful not to go too short so the mech pivot still has a little movement left at full suspension compression in your largest sprocket