Shimano, we have a problem.
- Thread starter Dakotadog
- Start date
aaronrryan
New Member
Yes, Hanger is straight. I adjusted the Derailleur and checked chain length as described at Shimano: https://si.shimano.com/api/publish/storage/pdf/en/dm/MARD001/DM-MARD001-03-ENG.pdf
Shifting works well, it's just chain slipping under load on 10t and 12t. all other cogs are fine.
Last edited:
Ive had this to on my xt 11 speed setup, as soon when i ride a couple hundred kms i get this skipping in lowerst gear. I was changing the smallest sprockets in less then 500 km.
Later on i switched to sram ex1 8 speed and thats been the best thing ive done yet! Its expensive but havent had any problems so far. Because i ride alot in the smallest gears, the biggest gears get allmost no wear so i can get the most out of the casette.
I now just change the smallest sprockets( 16€ for the set) around 1200km. Chain have just reached 0.3 wear om round that time.
Many on here will say its bad and way to expensive but for my usage its been more durable especially the smaller sprockets.
Only downside is that somewhere in the casette there is a big gap between 2 sprockets but once u adjust to that all is fine
I think many of think the EX1 was a good concept, but not executed well. Its a shame IMO they didn't revisit the idea with 9/10 speed as for me the Jumps in gearing on the 8 speed where annoying.
A lot of us on here think that the optimum gearing for an EMTB would be a robust 9 or 10 speed, and you can cobble something like this together out of what's on the market.
A lot of us on here think that the optimum gearing for an EMTB would be a robust 9 or 10 speed, and you can cobble something like this together out of what's on the market.
Chain skipping can really only be caused by one thing. And that is insufficient chain tension, possibly in combination with a worn cassette. Yes, the 12 speed drivetrains in my opinion arent suitable for Emtb. They are pushed to there limits, and were never designed to handle the amount of torque seen with ebikes.
Having said that my SLX 12 speed lasted me 4000km without any problem whatsoever. And at that time it was still running great, but i thought it would be wise to replace the chain. Bad decision, because that was when the chain skipping started on the 5 smallest sprockets. Lesson learned, dont mix old cassette with new chain. Replaced the cassette too, and all works perfect again.
So a new 12spd chain and cassette shouldnt skip. If it does im wondering if the chain tension is too low. A derailleur with insufficient spring tension could cause this. When i was servicing my XT derailleur i saw that the spring housing actually has a hole in it allowing moisture and water to enter pretty easily. As a result the spring can corrode pretty easily.
Also, maybe a wrong adjusted B-tension could reduce chain tension, but im not sure of that.
Chain length can also influence chain tension, so make sure that is ok too.
Anyway, i too would like to see something like a 1x9 drivetrain with wider chain and cogs. We need stronger longer lasting gears on an emtb, not more gears (12 is way too much if you ask me).
So if there are any options for the microspline hub im all ears. I think there is a Box 9 spd drivetrain out there but not compatible with microspline?
Having said that my SLX 12 speed lasted me 4000km without any problem whatsoever. And at that time it was still running great, but i thought it would be wise to replace the chain. Bad decision, because that was when the chain skipping started on the 5 smallest sprockets. Lesson learned, dont mix old cassette with new chain. Replaced the cassette too, and all works perfect again.
So a new 12spd chain and cassette shouldnt skip. If it does im wondering if the chain tension is too low. A derailleur with insufficient spring tension could cause this. When i was servicing my XT derailleur i saw that the spring housing actually has a hole in it allowing moisture and water to enter pretty easily. As a result the spring can corrode pretty easily.
Also, maybe a wrong adjusted B-tension could reduce chain tension, but im not sure of that.
Chain length can also influence chain tension, so make sure that is ok too.
Anyway, i too would like to see something like a 1x9 drivetrain with wider chain and cogs. We need stronger longer lasting gears on an emtb, not more gears (12 is way too much if you ask me).
So if there are any options for the microspline hub im all ears. I think there is a Box 9 spd drivetrain out there but not compatible with microspline?
aaronrryan
New Member
I ended up putting a 36t chainring on, and now I rarely use the 10t and 12t cogs.
I played with the chain tension, even went as far and shortening the chain too short just to see if it helps, and it doesn't.
I put a new chain with a new cassette and it happens still. Friend of mine got a brand new 2021 Levo Comp, so stock SLX 12 speed, and it skips on the first rides.
We are both heavy guys, I'm 230lbs and he's 265lbs, so maybe it's the amount of torque we are applying.
But in the meantime, I'm OK with using my 36t chainring to mitigate the issue.
I played with the chain tension, even went as far and shortening the chain too short just to see if it helps, and it doesn't.
I put a new chain with a new cassette and it happens still. Friend of mine got a brand new 2021 Levo Comp, so stock SLX 12 speed, and it skips on the first rides.
We are both heavy guys, I'm 230lbs and he's 265lbs, so maybe it's the amount of torque we are applying.
But in the meantime, I'm OK with using my 36t chainring to mitigate the issue.
Andy.M
Member
Sorry, I'm not up on the terminology. What does the chain skipping or slipping mean?
aaronrryan
New Member
Under load on the gears 11 (12t cog) and 12 (10t cog) the chain will slip or skip a tooth every once in a while.
as demonstrated in the video
This is with Turbo on and applying 720watts of power to the wheels.
It doesn't skip with lighter power applied.
aaronrryan
New Member
In my case, it's not about changing cogs, it's skips staying on the same cog. It's not an alignment issue.
I'm assuming it too much tension pulling the chain forward and up and off the cog.
I have the 70Nm E8000 motor, and i only weigh 74kg. So the amount of force on the chain, even when standing on my pedals, would be less than yours.
So im not sure what the answer is here.
Maybe we need stronger springs inside the derailleur? Perhaps in the future we will see ebike specific drivetrains from Shimano?
So im not sure what the answer is here.
Maybe we need stronger springs inside the derailleur? Perhaps in the future we will see ebike specific drivetrains from Shimano?
Andy.M
Member
Ah I see!
So as a lay-man, tell me if I'm barking up the wrong tree, I see that it only happens on the smaller cogs. So I'm imagining that the chain is only gripping on around half the teeth so on a 12 tooth that would be around 6 teeth in the chain. On the lowest gear there could be around 46 teeth so getting on for 4 times as many teeth in the chain. So I would imagine the physics of friction or lack of it in only 6 teeth are coming into play?
So as a lay-man, tell me if I'm barking up the wrong tree, I see that it only happens on the smaller cogs. So I'm imagining that the chain is only gripping on around half the teeth so on a 12 tooth that would be around 6 teeth in the chain. On the lowest gear there could be around 46 teeth so getting on for 4 times as many teeth in the chain. So I would imagine the physics of friction or lack of it in only 6 teeth are coming into play?
I can confirm this problem aswell. Even registered, to post and share my experience so far.
I have a Cube 120 stereo hybrid SL 625. I have transformed the bike to a nice sleeper with carrier, lights etc.
Bosch Gen 4, tuned, shimano XT 8100 derailleur, cassette, shifter.
Crusing around speed 35-40 km/h, gear 8-12. Mostly 11-12. Bike weights 25kg plus me around 100kg.
It started skipping gear 12 after 600km, adjusted the derailleur. The skipping was gone for a while but it came back.
Thought I was doing the adjustment wrong and went to my local bike shop. They fixed it, but like last time after a while it came back.
Started to put less load on gear 12 and more on 10/11 for getting up to my desired speed and then switch to 12 for cruising on that speed.
Chain failed me, upgraded to the XTR 9100, the problem was still there and got worse.
Around 800km the 12 gear was useless, 10 and 11 are starting to have the same behavior.
Now at 1200km the 10,11 and 12 are really worn out I guess skipping all the time.
I did not expect it to worn out so fast.
So what are the alternatives.
Buy new sprockets when the skipping start to get to unrideable state, or upgrade the system to a much more rigid e-mtb casette like the Eblock from sram.
Right, that does not come cheap at all. So new wheel, for the right hub system, stronger cassette and keep the rest of the shimano system?
Before blaming the tune, think about the same model Cube has, kathamandu S-pedelec (45). Comes with shimano SLX CN-M7100.
New XT 8100 is about 150 euro and sprocket for 11/12 combo around 25 euro.
The sprockets are pretty much sold out everywhere, so maybe this big demand on those parts wakes up shimano and build a specific strong emtb cassette etc
Anyhow, that´s my story with this drivetrain so far.
I have a Cube 120 stereo hybrid SL 625. I have transformed the bike to a nice sleeper with carrier, lights etc.
Bosch Gen 4, tuned, shimano XT 8100 derailleur, cassette, shifter.
Crusing around speed 35-40 km/h, gear 8-12. Mostly 11-12. Bike weights 25kg plus me around 100kg.
It started skipping gear 12 after 600km, adjusted the derailleur. The skipping was gone for a while but it came back.
Thought I was doing the adjustment wrong and went to my local bike shop. They fixed it, but like last time after a while it came back.
Started to put less load on gear 12 and more on 10/11 for getting up to my desired speed and then switch to 12 for cruising on that speed.
Chain failed me, upgraded to the XTR 9100, the problem was still there and got worse.
Around 800km the 12 gear was useless, 10 and 11 are starting to have the same behavior.
Now at 1200km the 10,11 and 12 are really worn out I guess skipping all the time.
I did not expect it to worn out so fast.
So what are the alternatives.
Buy new sprockets when the skipping start to get to unrideable state, or upgrade the system to a much more rigid e-mtb casette like the Eblock from sram.
Right, that does not come cheap at all. So new wheel, for the right hub system, stronger cassette and keep the rest of the shimano system?
Before blaming the tune, think about the same model Cube has, kathamandu S-pedelec (45). Comes with shimano SLX CN-M7100.
New XT 8100 is about 150 euro and sprocket for 11/12 combo around 25 euro.
The sprockets are pretty much sold out everywhere, so maybe this big demand on those parts wakes up shimano and build a specific strong emtb cassette etc
Anyhow, that´s my story with this drivetrain so far.
Yeah its becoming a big problem i think.
You can get a SLX cassette for around €80 - €90 which is the cheaper option compared to the XT.
The 10 and 12 cogs can be bought as a set for around €25 (XTR only) as you mentioned, all sold out...
The 14, 16 and 18 you can get in SLX / XT quality (they seem to be identical?) for around €3,- each.
(Is there actually a difference in XTR, XT and SLX for the small cogs?)
But that sadly still wouldnt solve the problem for many that have these gears fail after a couple of hundred kms.
IMO this problem could be aggravated by low chain tension. Perhaps some of the unlucky ones just have a derailleur with less tensioning force. It is expected that there is variation in spring tension inside the derailleur as a result from the manufacturing process. So someone with a less springy derailleur could experience skipping sooner. Other factors would be riding weight (the amount of force applied to the pedals) and motor torque (i guess my weaker E8000 is at an advantage here, lol).
But obviously the primary problem is just that the mechanism is pushed too far to its limits.
A true solution imo would be a emtb specific 9 speed system. Wider chain and cogs, more resistant to high torque, less wear, less chain stretch etc. And perhaps we need derailleurs that provide higher chain tension?
You can get a SLX cassette for around €80 - €90 which is the cheaper option compared to the XT.
The 10 and 12 cogs can be bought as a set for around €25 (XTR only) as you mentioned, all sold out...
The 14, 16 and 18 you can get in SLX / XT quality (they seem to be identical?) for around €3,- each.
(Is there actually a difference in XTR, XT and SLX for the small cogs?)
But that sadly still wouldnt solve the problem for many that have these gears fail after a couple of hundred kms.
IMO this problem could be aggravated by low chain tension. Perhaps some of the unlucky ones just have a derailleur with less tensioning force. It is expected that there is variation in spring tension inside the derailleur as a result from the manufacturing process. So someone with a less springy derailleur could experience skipping sooner. Other factors would be riding weight (the amount of force applied to the pedals) and motor torque (i guess my weaker E8000 is at an advantage here, lol).
But obviously the primary problem is just that the mechanism is pushed too far to its limits.
A true solution imo would be a emtb specific 9 speed system. Wider chain and cogs, more resistant to high torque, less wear, less chain stretch etc. And perhaps we need derailleurs that provide higher chain tension?
steve_sordy
Wedding Crasher
SRAM do an 8-speed one called the EX1 I believe. It gives you all you ask for, at a price.
Personally I don't like it as I could never find a gear I liked, I always seem to be in the wrong one.
SRAM EX1 Review: 8-gear drivetrain for E-MTBs
We've tested the first dedicated E-MTB drivetrain, the SRAM EX1, on various bikes over the past few weeks. Here's what we think.
ebike-mtb.com
I think I will aim for a new SLX cassette with a new chain, service the derailleur and lets see how long it takes before it wears out.
SRAM do an 8-speed one called the EX1 I believe. It gives you all you ask for, at a price.
Personally I don't like it as I could never find a gear I liked, I always seem to be in the wrong one.
SRAM EX1 Review: 8-gear drivetrain for E-MTBs
We've tested the first dedicated E-MTB drivetrain, the SRAM EX1, on various bikes over the past few weeks. Here's what we think.
How many cogs where you running front ? Gen4?
Well, only the cassette goes for like 400 euro. Tuning the motor for the new gear ratios...lot of hassle.
The system was released 2016. Its 2021, time for more new strong systems
As said, a 9/10 speed with the last gear having 11cogs at least.
I run this drive train on my emtb (tuned bosch gen2). The retail price of the cassette is at 490€ i believe, but you can get it way cheaper in germany ( paid 310 for cassette and chain).I think I will aim for a new SLX cassette with a new chain, service the derailleur and lets see how long it takes before it wears out.
How many cogs where you running front ? Gen4?
Well, only the cassette goes for like 400 euro. Tuning the motor for the new gear ratios...lot of hassle.
The system was released 2016. Its 2021, time for more new strong systems
As said, a 9/10 speed with the last gear having 11cogs at least.
Ive had a 20t chainring upfront that was good for speeds at 50-60km/h but i later switched to a 18t cuz the chainring was to expensive (around 95€) to replace.
I usually order my bike parts from Germany.
It would awesome tho, for my scott egenius 730. But never had any problems with the 11speed NX drivetrain there.
The system was designed for gen 2 bosch etc, haven´t sourced out someone with the gen4 yet to give us feedback. So risky spending that amount of money for trial and error. It´s starting to get warmer here soon again, and want to have the ride ready for action.
For gen 4 you have 36/38T chainrings. 38 being the most common, I even found a 42T one.
The only difference is the front chainring, im sure there are narrow wide chainrings out there for gen 4.
The rest is just the same as all the other drivetraims put there, just less gears.
I mainly use the smaller gears anyway wich give me such a low wear on the bigger gears. I get away with just replacing the cogs
SRAM do an 8-speed one called the EX1 I believe. It gives you all you ask for, at a price.
Personally I don't like it as I could never find a gear I liked, I always seem to be in the wrong one.
SRAM EX1 Review: 8-gear drivetrain for E-MTBs
We've tested the first dedicated E-MTB drivetrain, the SRAM EX1, on various bikes over the past few weeks. Here's what we think.
Agree with that.
I do find it odd though, that after developing an e-mtb specific 8 speed (only need 8 as it's an e-bike apparently) drivechain that the most common drivechain fitted to e-mtb's now is a 12 speed...
steve_sordy
Wedding Crasher
Others will know for sure, but I had believed that the need for a stronger chain started with a wider one and that meant 8-speed. They could have gone 9-speed, but the chain would have had to be narrower and therefore weaker. The range is 11-48 (436%) which is surely wide enough for most riders. But I just could not get on with the big gaps.
An 8-speed chain has 7 gaps, and on that range implies an average shift of 23%.
My 11-46T 11-speed has an average shift of 15%, which is pretty much the standard shift % (for mtbs at least). That may seem a small difference, but it's an average 50% bigger shift each time. I only tried an EX1 for a hour or so and I may have got used to it, but it felt so so uncomfortable that it may have taken some time. It reduced my enjoyment of the bike.
Even the 10-50T 12-speed has an average shift of just under 16%.
I believe the ex1 chain is 10 speed. It also uses a 10 speed powerlock
steve_sordy
Wedding Crasher
Ahh, I have never heard or read that before. How fascinating! I thought that someone would know more about this for sure. It being an 8-speed transmission, I had assumed it was an actual 8-speed chain.
You know what they say about ASSUME, it makes an ASS out of U and ME
Later Edit: It still doesn't make sense to me to go for strength and then compromise by fitting a 10-speed chain.
Last edited:
I used mine for about 1k miles, to be fair it was still shifting ok when I changed it, also sold the complete kit for £115 on ebay.
nasamorpheus
Member
Sram steel last forever
Hello everyone
My experience with Shimano's SLX bothers me a lot, I changed casts 3 times, at the bike shop, in less than 1500 km it is important to note that I am a new rider and walk only for dirt roads, do not climb mountains or singles and have no medical strength in my legs or fitness Physical.
Even I myself was not one to skip the SLX Cassette 7100, whenever an experienced friend would take the bike for 10 minutes of experience he would come back and tell me I had a skip. Would show me the jump after exerting some force on my missing legs.
I'm desperate and mentally broken I stopped riding, and considering selling the bike and suing the store and against Shimano, I would love to cooperate.
My experience with Shimano's SLX bothers me a lot, I changed casts 3 times, at the bike shop, in less than 1500 km it is important to note that I am a new rider and walk only for dirt roads, do not climb mountains or singles and have no medical strength in my legs or fitness Physical.
Even I myself was not one to skip the SLX Cassette 7100, whenever an experienced friend would take the bike for 10 minutes of experience he would come back and tell me I had a skip. Would show me the jump after exerting some force on my missing legs.
I'm desperate and mentally broken I stopped riding, and considering selling the bike and suing the store and against Shimano, I would love to cooperate.
EMTB Forums
Latest articles
-
Introducing the Forestal e-Cygnus - a downcountry and XC emtb
The new Forestal e-Cygnus is a slightly unusual emtb. It comes in two... -
2025 M1 Sporttechnik EN 8.0 review
The M1 EN is one of four M1 models built on the same frame. Well, it’s...