Shimano, we have a problem.

[Dakotadog]

My breakup with Shimano drivetrain.
A little background:
I have been Riding Shimano drivetrain since I can remember. I had a couple of bikes that came with SRAM drivetrain which Inevitably failed somehow so I got to the point that if I made a purchase of a bike that came with SRAM my immediate instinct was to remove the Sram components and install Shimano. I even adopted the mantra “friends don’t let friends ride SRAM“.

This past year I purchased my first E-bike a Norco Range VLT-C1. The bike came with SRAM GX which I immediately removed as well as the SRAM code brakes. I replaced the Brakes with Shimano Saints and upgraded the drivetrain to shimano 12 speed XTR shifter, derailleur And chain with a XT cassette 10-51.

The new drivetrain on the bike seemed like the perfect match, the shifting was crisp and flawless. Then came the chain skip.

After the second ride I found my chain would skip in the 10 tooth cog. This progressively got worse and extended to the 12 tooth cog as well.
determined to find some damaged part that would cause this I began the process of replacing parts to try and find the culprit.
I replaced the following parts in this order:
rear derailleur hanger
rear cassette
new chain
new chainring
I also had 2 bike shops verify the rear Derailleur was in proper adjustment and alignment.

After the new parts were installed my first ride out the drivetrain worked great for the first half of the day but began to skip again by the end of the day. I also noticed unusual wear on the 10 and 12 tooth cog which I would describe as stripped out gears.
Shimano tech support was contacted and they stated that they had never seen this problem before but they were willing to warranty the failed parts.
Determined to fix the problem I replaced the following parts:
rear derailleur
shifter
rear cassette
new chain

The parts were installed at the shop and all settings were checked.
Next ride out the cassette did not make it though the first 5 miles before it began to strip out again.
I started to think that perhaps it was a problem with the bike. I contacted the Norco rep and again they had not heard of any problems.

Running out of options I finally made the decision to do the unthinkable, swap the drivetrain out for a SRAM.

I had the shop install a SRAM XO1 12 speed 10-50.
I am now 5 rides into the new drivetrain. I have put the new drivetrain through the paces and have not had a single hiccup. I am still dealing with the stages of grief over losing my shimano drivetrain but the change was obviously for the best.

I am finding it hard to believe that my e-bike is the only one having problems with the Shimano 12 speed. My wallet is also heartbroken over the loss of 1500$ worth of junk shimano parts.

 

[Jackware]

Isn't XTR a Rapidfire shifter? It probably wasn't the best shifter for an ebike. The Sram ebike version of the GX is single shift only.
Maybe the shop and Shimano were too polite to say you may need to relearn your shifting technique now you're on an ebike.

 

[Dakotadog]

Isn't XTR a Rapidfire shifter? It probably wasn't the best shifter for an ebike. The Sram ebike version of the GX is single shift only.
Maybe the shop and Shimano were too polite to say you may need to relearn your shifting technique now you're on an ebike.

I Recognized that shifting multiple gears at a time could be a problem and shifted appropriately 1 gear at a time
The chain skip would happen while on long descents in a single gear and were not related to shifting

 

[Dirtnvert]

I think theyre speccing rapidfire on emtb because they shift quite smooth. Lots of chatter with the clutch on the derailleurs not being sealed as well as past clutches and theyre corroding and needing fairly regular greasing. I wonder if the clutch may have played a part in your drivetrain failures? My new bike is being shipped shortly and it has slx groupset. Like ypu ive been on shimano for years, since SIS when they took over suntours market share in the 80's

 

[Dakotadog]

I think theyre speccing rapidfire on emtb because they shift quite smooth. Lots of chatter with the clutch on the derailleurs not being sealed as well as past clutches and theyre corroding and needing fairly regular greasing. I wonder if the clutch may have played a part in your drivetrain failures? My new bike is being shipped shortly and it has slx groupset. Like ypu ive been on shimano for years, since SIS when they took over suntours market share in the 80's

I replaced the derailleur as well with a new one same result
And you are right the new EBikes are being spec’ed with Shimano XT 12 speed rapid fire

 

[Al Boneta]

Neither Shimano or SRAM are immune to problems.
Most of the time they are both reliable, but I have seen failures with both.
Ebikes eat chains and cassettes for breakfast and as long as you don’t shift like a hamfisted slack jawed twat, you can achieve acceptable levels of longevity.

 

[GrandesRoues]

Looks like they weren't enough tension in the chain for the smallest cogs.

 

[steve_sordy]

Lots of riders have ebikes that do not eat chains for breakfast. There was a thread on here not long ago on that very topic.
I have a Focus Jam 2 9.6 NINE and I did 1446 miles with only 0.375% stretch. I removed the chain and measured over 100 links. The cassette was worn though so I fitted a new chain on the new cassette. I have kept the old chain and when the current chain is worn I will replace it with the old one.

Many riders got higher mileages than me. I ride all year round in the UK and mostly in a sandy environment. I weigh 14.5 stone (92kg) in my riding kit.

 

[paquo]

Looks like they weren't enough tension in the chain for the smallest cogs.

i put full xt on my levo and it has worked out pretty well. In the instructions there is a specific way to set chain length, i would imagine that is critical to setup

 

[04fuxake]

I Recognized that shifting multiple gears at a time could be a problem and shifted appropriately 1 gear at a time
The chain skip would happen while on long descents in a single gear and were not related to shifting

Maybe the gear cable is catching slightly and ghost-shifting when the suspension is moving. The Shimano derailleur might be more sensitive to this than the SRAM one.

 

[GrandPaBrogan]

Once the chain starts skipping or hopping off the teeth of the smaller sprockets (12, 11, 10 T) the damage has already been done.

If you’re in the habit of hoofing an eBike on max ‘turbo’ settings on the smaller cassette gears, two things are occurring:

1) The torque you feel/think you’re applying and the torque your chain is actually experiencing are two different things. Pedal assist is deceptive... and can easily overload your drivetrain unbeknownst - even by twice as much.

2) In a typical derailleur setup, only HALF the number of teeth in any cog (sometimes less) are carrying the load (the chain pull). Unfortunately the inverse is true when it comes to ‘leverage strain’ whereby the larger cogs with more teeth actually require less torque to rotate the rear wheel. The smaller cogs with even lesser teeth require more torque to rotate the rear wheel - even more so for 29ners. Imagine what doubled extreme chain tension would do to just 5 teeth on an 11T cog, or just 4 teeth on a 10T cog? Teeth deformation and chain stretch damage will be accelerated.

Gotta remember to stay off the smallest gears and turbo modes when climbing or ascending. Leave the smallest cogs for high speed cruising on the flats, or be prepared to eat through those slim 11/12 speed chains and cassettes. That’s just the way it is with 80Nm+ motor eBikes...

 

[FSEngineer]

Had exactly this issue with 12 speed XT on my Spectral:ON, from brand new the chain would skip in the 10t gear. Whipped it straight back off and put the bits on ebay, gone back to 11 speed XT with an 11-46 steel sunrace cassette and not had an issue since. IMO the new 12 speed drivetrains from Shimano are not fit for purpose on an ebike (a friend recently bought a Merida E160 with XT 12 speed and killed two chains and a cassette within 20 miles from new in normal use).

 

[Jackware]

Had exactly this issue with 12 speed XT on my Spectral:ON, from brand new the chain would skip in the 10t gear. Whipped it straight back off and put the bits on ebay, gone back to 11 speed XT with an 11-46 steel sunrace cassette and not had an issue since. IMO the new 12 speed drivetrains from Shimano are not fit for purpose on an ebike (a friend recently bought a Merida E160 with XT 12 speed and killed two chains and a cassette within 20 miles from new in normal use).

Well that's conclusive proof right there.

 

[FSEngineer]

Well that's conclusive proof right there.

Not sure if that's sarcasm...

 

[nickfrog]

I also have conclusive proof that Shimano 12 speed is brilliant. I have done 1,000 miles on a full SLX tranny fitted to the Decoy and it hasn't missed a beat. Shifting is very crisp, in a 10 speed kind of crisp, unlike Shimano 11. Wear is still minimal which really surprised me.
I am amazed at the amount of kit and money spent by the OP. I would have started somewhere else frankly. Cable, hanger alignment, B screw...

 

[STATO]

I have many questions...

1. What terrain are you riding that you spend so much time in the 10t? if you spend so much time there perhaps a bigger chainring would be worth a look. (edit; realised you are US so 20mph assist limit, perhaps this is a bad side-effect of the higher limiter than EU market)

2. Why did you replace everything at once? Shimano gears work perfectly with SRAM cassette, you only needed to change that if the shimano cassette wasnt holding up to your riding.

3. What sort of shop lets a customer spend that sort of money without resolving the issue

 

[MrBrownstone]

Neither Shimano or SRAM are immune to problems.
Most of the time they are both reliable, but I have seen failures with both.
Ebikes eat chains and cassettes for breakfast and as long as you don’t shift like a hamfisted slack jawed twat, you can achieve acceptable levels of longevity.

I get the same wear life or better with chains and cassettes as I did on my acoustic bike. 3100 hard miles on my slx 11 speed drivetrain and just swapped out the original cassette after it saw 3 chain swaps over the course of 2900 miles.

 

[GrahamPaul]

Lots of chatter with the clutch on the derailleurs not being sealed as well as past clutches and theyre corroding and needing fairly regular greasing. I wonder if the clutch may have played a part in your drivetrain failures?

Certainly my experience with the 12sp SLX. The Shimano manual says it probably needs a regrease every 12 months. I'm lucky to get 12 days out of mine. Up until now I've been a fan of all things Shimano, but this one is a sod. The torque to the clutch is also hyper critical - and is not the same for the whole range of movement, which I guess isn't surprising as it uses a "clock spring" as the tensioner.

I've done around 4000km on the drive train using 2 chains in rotation. Still less than 0.5% chain stretch.

I see that the OP is from the USA, which would explain how he is using the 10t ring so much. That's 100% leg power in this part of the world - the motor has switched off 10km/hour ago.

 

[Dirtnvert]

Certainly my experience with the 12sp SLX. The Shimano manual says it probably needs a regrease every 12 months. I'm lucky to get 12 days out of mine. Up until now I've been a fan of all things Shimano, but this one is a sod. The torque to the clutch is also hyper critical - and is not the same for the whole range of movement, which I guess isn't surprising as it uses a "clock spring" as the tensioner.

I've done around 4000km on the drive train using 2 chains in rotation. Still less than 0.5% chain stretch.

I see that the OP is from the USA, which would explain how he is using the 10t ring so much. That's 100% leg power in this part of the world - the motor has switched off 10km/hour ago.

Definitely have to keep an eye on that then. I see on a vital mtb article, in the comments, a guy was using a grease gun on his. I seem to remember he was using slikoleum. I might have to consider putting a zirc fitting on the clutch cover and just shooting it with slikoleum on the regular. Something quick and ez and it could work better than it was designed to work

 

[GrahamPaul]

I might have to consider putting a zirc fitting on the clutch cover and just shooting it with slikoleum on the regular. Something quick and ez and it could work better than it was designed to work

I don't think you can do that. Shimano say to make sure that no grease gets between the chain stabilizer and the plate axle, else the clutch won't clutch... (page 36 of the maintenance instructions). I'm pretty sure what you're suggesting will ensure grease gets in there.

 

[MrBrownstone]

I leave the clutch off 100% of the time on my rear derailleur as I tend to pick up sticks often where I ride. 4 broken hangers since December in 3100 miles. Only one destroyed rear derailleur tho but I bet ida broken more with the clutch on and stiff as a board. Shifting is nicer with clutch off too. Light touch. Chain slap hasn’t been an issue and it’s very rough where I ride.

 

[Dirtnvert]

I don't think you can do that. Shimano say to make sure that no grease gets between the chain stabilizer and the plate axle, else the clutch won't clutch... (page 36 of the maintenance instructions). I'm pretty sure what you're suggesting will ensure grease gets in there.

Ya just spitballing. Maybe just pull the cover regurly and oil it . Just keep oil on it shouldnt cause any issue

 

[nasamorpheus]

Neither Shimano or SRAM are immune to problems.
Most of the time they are both reliable, but I have seen failures with both.
Ebikes eat chains and cassettes for breakfast and as long as you don’t shift like a hamfisted slack jawed twat, you can achieve acceptable levels of longevity.

PG-1230 steel cassettes can't be eaten by ebike easily.. but of course those high price, light ALU cassettes can Sometimes those top racing configuration aren't best for specific type of ebikes. Ebikes are extremely strong and they need some steel instead of very light and smooth shifting which XTR provides..Actually who need xtr on ebike cmon XTR is for racing, two races and sponsor buy new drivetrain.. But of course if you have 10k for bike why not spend another 1.5 for drivetrain.

 

[Al Boneta]

PG-1230 steel cassettes can't be eaten by ebike easily.. but of course those high price, light ALU cassettes can Sometimes those top racing configuration aren't best for specific type of ebikes. Ebikes are extremely strong and they need some steel instead of very light and smooth shifting which XTR provides..Actually who need xtr on ebike cmon XTR is for racing, two races and sponsor buy new drivetrain.. But of course if you have 10k for bike why not spend another 1.5 for drivetrain.

Your statment is only based on your personal experience. Which is considerably less than mine.
I have been a bike technician for 30 years and a master technician for the last two decades. I have been the service manager and the GM at my shop for the last 18 years.
I am constantly recommending to newbie riders to use steel cassettes and eBike specific chains. Too many riders shift under load and prematurely wear out drivetrain components.
I really don’t know why you’re winking at me. With the exception of my S-works, all of my bikes have 1x9 Microshift drivetrains.

 

[Dirtnvert]

Knut's last vid is pretty interesting. The money you save with a steel cassette is best used for a higher level chain. Good breakdown on the numbers

 

[nasamorpheus]

Your statment is only based on your personal experience. Which is considerably less than mine.
I have been a bike technician for 30 years and a master technician for the last two decades. I have been the service manager and the GM at my shop for the last 18 years.
I am constantly recommending to newbie riders to use steel cassettes and eBike specific chains. Too many riders shift under load and prematurely wear out drivetrain components.
I really don’t know why you’re winking at me. With the exception of my S-works, all of my bikes have 1x9 Microshift drivetrains.

Sorry that wasnt my purpose I "quoted" wrong person, you, but I wrote for the Dakotadog who spent around 10k for his Norco Range VLT-C1 ebike.

 

[DrStupid]

Your statment is only based on your personal experience. Which is considerably less than mine.
I have been a bike technician for 30 years and a master technician for the last two decades. I have been the service manager and the GM at my shop for the last 18 years.
I am constantly recommending to newbie riders to use steel cassettes and eBike specific chains. Too many riders shift under load and prematurely wear out drivetrain components.
I really don’t know why you’re winking at me. With the exception of my S-works, all of my bikes have 1x9 Microshift drivetrains.

Hey Al, how do you think the microshift 9 speed compares to a Hyperglide 10 speed in longevity and performance?

I'm currently getting about 300-400 miles from a typical 10 speed chain. This is not a complaint, as I'm almost constantly in mud, and typically full gas mode too.

The 9 speed microshift doesn't seem to get a lot of playtime around here, and I'm curious.

 

[luna87824]

Not sure if that's sarcasm...

 

[Al Boneta]

Hey Al, how do you think the microshift 9 speed compares to a Hyperglide 10 speed in longevity and performance?

I'm currently getting about 300-400 miles from a typical 10 speed chain. This is not a complaint, as I'm almost constantly in mud, and typically full gas mode too.

The 9 speed microshift doesn't seem to get a lot of playtime around here, and I'm curious.

It works fine and even if you bend the hanger it still shifts without complaint. I use a 9 speed ebike chain and the all steel cassette and it’s lasted more than 2000 miles

 

[aaronrryan]

I'm having the same issue as the first poster. I got a used 2021 Levo Comp with SLX 7100 12 speed setup with 500 mile on it. I noticed that both 10t and 12t cog would skip if I applied medium-light pressure in turbo mode (going 19-20mph on flats).

So I bought a new replacement SLX CS-M7100 51t cassette and a new SLX Chain and tried it out and the 10t is still skipping but 12t is skipping less, though still doing it at times. I also got a new XT M8120 Wheelset and the issue is the same on the new wheelset.

Has anyone having this issue try switching to a SRAM cassette and see if the skipping still happens?