Shimano EP8 Spindle Failures and People getting injured. Where to now?

Hitorogoshi

Active member
May 19, 2020
116
122
South Africa
I am starting a thread on this matter as I believe it deserves some headline. As we all know the EP8 spindle has been manufactured very poorly. All brands of cranks are breaking them. People are getting hurt and Some of us fear riding our expensive bikes.

post from other thread for insight...

This issue is serious
@e*thirteen Components

Where do we turn to now? Shimano and E13 are pointing fingers at each other while people are getting hurt.
Yes you cover the warranty and service is great, but this does not fix the issue. These problems should not be happening.

Shimano and you guys need to come to the party. I'm sitting with a fkn expensive bike I am too afraid to ride because I could snap my leg or ankle. Do you not see the seriousness in that? It blows my mind how companies handle things like this.

I don't want a patch fix that suggests it "may" solve the problem. I want a definitive answer that reassures my safety on the bike and it's components. This has gone on for far too long.

@Rob Rides EMTB - I think you need to address this issue in all seriousness and do some investigating. The EP8 Facebook group is rife with problems on the matter. People are getting injured with EP8 splines breaking, not only on E13 cranks but on other brands too.
The EP8 Spindle is a manufacturing joke. This is a safety concern to ALL EP8 riders. Especially on the birth models of the motor.

How do I approach this matter now with Commencal and Shimano? All my hard earned savings for a bike that's not safe to ride. I'm quite perplexed.
 

Hitorogoshi

Active member
May 19, 2020
116
122
South Africa
Shimano is simply ignoring these failures and passing the buck. A simple quick search on all platforms sees multiple riders across multiple brands experiencing crank and spindle failures. You only need to visit their facebook ebike page to see people post about it randomly on their posts. I'm actually sickened by this. It's a SAFETY CONCERN!!!! not a mere product failure.
 

Shjay

Well-known member
Apr 30, 2019
835
488
Kent
I think the problem is running aftermarket cranks on the EP8, mine came with E13 cranks, they have never come off but I have just put on the Shimano cranks but not had a test ride yet! I swapped in my garage & wasn’t sure if their was a feint crank on the spindle on drive side around the hole on the cranks or not! I am currently away from the bike for a few days & will check again in daylight when I return! I fitted the E13 cranks myself to 14nm with a torque wrench doing each bolt a bit at a time!! I am a Cytech mechanic
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,362
8,588
Lincolnshire, UK
I think the problem is running aftermarket cranks on the EP8, mine came with E13 cranks, they have never come off but I have just put on the Shimano cranks but not had a test ride yet! I swapped in my garage & wasn’t sure if their was a feint crank on the spindle on drive side around the hole on the cranks or not! I am currently away from the bike for a few days & will check again in daylight when I return! I fitted the E13 cranks myself to 14nm with a torque wrench doing each bolt a bit at a time!! I am a Cytech mechanic
I am assuming that you mean "faint crack" on the spindle and not "feint crank". Typical autotype problem.
 

Shjay

Well-known member
Apr 30, 2019
835
488
Kent
I am assuming that you mean "faint crack" on the spindle and not "feint crank". Typical autotype problem.
Yes haha 😂 can’t feel it with finger nail but will give it a proper check & keep an eye on it!, I guess if people have had issues with Shimano cranks then the damage has already been started by the E13 cranks
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,362
8,588
Lincolnshire, UK
I came across this interesting article on Bike Radar today.

Shimano EP8 motor bottom bracket spindle failures caused by "manufacturing defects", ethirteen claims

e13 have used independent analysis to confirm that it is a design defect in the spindle and not caused by e13cranks. They shared this with Shimano who said that they were aware of 49 spindle failures and not one was associated with a Shimano crank. Shimano stated that only Shimano cranks were tested and approved for the EP8 motor.
Also, that if you have an EP8 spindle failure with a non-Shimano crank and/or have a non-Shimano crank on your unfailed EP8 spindle and are concerned, then contact the bike manufacturer. My understanding from the Bike Radar article is that Shimano are saying it is nothing to do with them.

Bike Radar also chased up some of the manufacturers that use non-Shimano cranks on EP8 motors. At the time of going to press only Commencal had replied. My reading of their response was that they were doing everything that you and I would hope. That includes replacing your e13 cranks for Shimano ones, even if you have not had a failure. Go Commencal! :love:
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,105
4,636
Weymouth
Can anyone explain how the hole in the spigot is used with Shimano cranks? My understanding is that some 3rd party cranks do not use it.
If the Shimano cranks include a locator pin that sits snugly in that hole I can see from an engineering point of view how that might reinforce the free end of spigot beyond the hole against torsional forces. I could also envisage that the ( expected) torsional force would be concentrated on the outer edge of the spigot if there was also a coincidental tendency for the cranks to come loose.
The usual method of securing a crank on a spline ( spigot) is for the cranks to be pushed hard against the inner end of the spigot which is slightly ramped......or sometimes has a mild taper...or both. The Shimano method shares the fixing loads between a fairly low torque pre load bolt and 2 clamp bolts coupled with a split collar design.
I see the opportunity for some installation problems with that design ( compared to a single high torque end bolt).
The Shimano style preload bolt has a seal. It is unlikely the pre load torque will remain accurate since that seal will compress over time, so I would not use the seal. The bolt is factory threadlocked......I would remove that threadlock and apply my own for 2 reasons. Firstly there is no knowing how long that bolt has been lying around before being used, and secondly, the factory threadlock being dry will prevent an accurate torque being applied whereas a wet ( new) threadlock application will lubricate the threads. This is especially the case with the low torque setting of that bolt. (n.b. the new threadlock application will not be effective unless left undistrurbed for 24 hours).

Then there is the question, should the spigot splines be greased? Normally, they should be to ensure the crank slides over the splines without resistance and to enable the pre load torque to be accurate. It also provides corrosion protection. In this case however, a significant part of the fixing method is the clamping force applied by the 2 bolts and split crank collar. You would want high levels of friction between the crank collar and the splines and because the crank collar is split it will not add resistance to the pre load bolt if not greased.
So, I would apply a little grease only on the slight ramp on the inner edge of the spigot, and leave the majority of the splines clean.
 

RustyIron

E*POWAH Elite World Champion
Jun 5, 2021
1,477
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La Habra, California
Can anyone explain how the hole in the spigot is used with Shimano cranks?

I'm not certain on the eMTB motors, but Shimano Hollowtech cranks had a hole in them, as well. On the crank arm, the clamping slot is rather wide. Into the slot fits a "safety tab," shown in the attached image below. The clamping bolts hold the tab in about the right spot, and that little pin you see fit into the hole of the shaft. The intention is that the pin in the hole will keep the crank arm from falling off.

To me, this seems like the dumbest thing ever. If they can't build a clamp that will stay tight on a splined shaft, I would think that they would redesign their clamp, rather than adding a stupid little pin encased in plastic.


iu.jpeg
 

Bigtuna00

Active member
Nov 27, 2019
556
336
CA
Interesting summary. However you left out the part where Shimano said they know why the failures are happening, and the cause is the design of the e*thirteen cranks.

I'm not saying I believe either side tbh. More than likely the real story is they're both at fault. But IMO you left out the most important part, from Shimano's perspective.

Does Shimano know why the spindles are snapping?

“Yes, we understand how and why spindle breakage may occur when some non-Shimano cranks are used with our DU-EP800 drive unit. Non-recommended 3rd party cranks can make a crack in the spindle because the difference in design from Shimano’s crank causes increased stress around the spindle hole. Under this condition, with each ride the crack can expand, and this can result in a spindle breakage.”
 

boBE

Active member
Apr 12, 2020
415
361
FL
Yes haha 😂 can’t feel it with finger nail but will give it a proper check & keep an eye on it!, I guess if people have had issues with Shimano cranks then the damage has already been started by the E13 cranks
Maybe there is a local metalworking shop that can do a zyglo check to confirm if there is a crack.
 

RustyIron

E*POWAH Elite World Champion
Jun 5, 2021
1,477
2,346
La Habra, California
However you left out the part where Shimano said they know why the failures are happening, and the cause is the design of the e*thirteen cranks.

There are SO MANY other industries that specifically mandate the use of OEM equipment and forbid the use of third party parts. It kind of makes sense. The manufacturer has no control over knock-off parts. If e*thirteen is the common factor in all the shaft failures, then we just shouldn't use e*thirteen cranks, we should stick with Shimano.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,362
8,588
Lincolnshire, UK
Interesting summary. However you left out the part where Shimano said they know why the failures are happening, and the cause is the design of the e*thirteen cranks.
..................................
Leaving out that bit was not deliberate editing on my part to make a point. I was trying to give a few highlights to encourage people to read the full article. I was deliberately not trying to favour either side, merely reflecting what was in the article. I was however in favour of Commencal's reported response to the issue!
 

Manc44

Member
Jun 22, 2021
120
39
Manchester
This is why I don't use a Hollowtech 2 crank which is basically what that EP8 looks like to me, with the same shallow looking ridges where it meshes together. I never had a Hollowtech 2 crank slip on me but I can see just from looking at it, there's a good chance it might happen.

STUPID design...

UscUoTc.jpg
 
Last edited:

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,105
4,636
Weymouth
To my mind the most plausible explanation for a crack to appear emanating from the hole in the spigot, and on occasion complete failure of the spigot, is the crank becoming loose. Explanations for the crank coming loose are likely due to insufficient pre load....in turn caused by the seal compressing and dry threadlock on the pre load nut, preventing accurate pre load in the first place. I detailed in my post further up this thread how I think he crank installation should be done. From an emgineering design point of view I see no purpose in the hole in the spigot but that is something only Shimano can change.........better still Shimano could adopt the Isis spigot design for the EP8 and specify standard ISIS cranks!! The current Shimano desing is reminiscent of the old cotter crank design!!
 

Planemo

E*POWAH Elite
Mar 12, 2021
575
660
Essex UK
This is why I don't use a Hollowtech 2 crank which is basically what that EP8 looks like to me, with the same shallow looking ridges where it meshes together. I never had a Hollowtech 2 crank slip on me but I can see just from looking at it, there's a good chance it might happen.

Like you, I've had zero issues with Hollowtech, and I've had quite a few. Unlike you, I do not feel it is a bad design though. The splines do indeed look shallow and small, but you would be amazed how much torque the system can handle with a correctly fitted crank arm.

A bit like clutch plates on cars - I was always amazed how all that power (eg 500bhp+ Cosworth) goes though a splined shaft 1" in diameter. But fail they don't..
 

RustyIron

E*POWAH Elite World Champion
Jun 5, 2021
1,477
2,346
La Habra, California
From an emgineering design point of view I see no purpose in the hole in the spigot but that is something only Shimano can change.........better still Shimano could adopt the Isis spigot design for the EP8 and specify standard ISIS cranks!!

Wrenches, spanners, ferrules, olives, and now spigots!

In the interest of concise communication, please help me out here. To me, spigots are faucets. I understand what your talking about because of the context of the conversation. Can "spigot" mean something other than a splined shaft? Suppose I come across and Englishman sitting in the middle of the trail, and he says, "Bloody hell! I broke my blooming spigot!" Is there anything else he could be talking about?
 

RustyIron

E*POWAH Elite World Champion
Jun 5, 2021
1,477
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La Habra, California
A bit like clutch plates on cars - I was always amazed how all that power (eg 500bhp+ Cosworth) goes though a splined shaft 1" in diameter. But fail they don't..

Torque converters are splined. Some axles are splined. And in these applications, the fitting is not even clamped. Because there are plenty of instances of cracking at the hole, and the usage of the hole appears to be deprecated, it makes sense to just get rid of it. I was told that Shimano DID get rid of the holes on the newer motors, which would make this conversation moot. I looked at mine, and I can see no hole, but there's a chance that it's just covered up by the preload screw. I'm not interested in taking it apart just to satisfy my curiosity.
 

Planemo

E*POWAH Elite
Mar 12, 2021
575
660
Essex UK
Torque converters are splined. Some axles are splined. And in these applications, the fitting is not even clamped. Because there are plenty of instances of cracking at the hole, and the usage of the hole appears to be deprecated, it makes sense to just get rid of it. I was told that Shimano DID get rid of the holes on the newer motors, which would make this conversation moot. I looked at mine, and I can see no hole, but there's a chance that it's just covered up by the preload screw. I'm not interested in taking it apart just to satisfy my curiosity.

I agree, the hole seems pointless and will risk instigating cracks. My post however was in relation to the insinuation that splines are a bad idea. Which they aren't.
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,105
4,636
Weymouth
Wrenches, spanners, ferrules, olives, and now spigots!

In the interest of concise communication, please help me out here. To me, spigots are faucets. I understand what your talking about because of the context of the conversation. Can "spigot" mean something other than a splined shaft? Suppose I come across and Englishman sitting in the middle of the trail, and he says, "Bloody hell! I broke my blooming spigot!" Is there anything else he could be talking about?
:ROFLMAO::ROFLMAO:.......sorry for the confusion!! In the UK at least a spigot is the end of pipe that fits onto another pipe and I used that term because the splined shaft of the motor is in fact the (near ) equivalent of crankshaft ( crank) .....but most of us abbreviate the crank arms to just.. "cranks" so we end up with a confusion of terms!! The exposed/splined section of the crankshaft therefore equates to being a spigot over which the crank arms fit.
I forget sometimes that things have different names even in other English speaking countries!!
 

RustyIron

E*POWAH Elite World Champion
Jun 5, 2021
1,477
2,346
La Habra, California
I forget sometimes that things have different names even in other English speaking countries!!

Dude! I collect old engines, and I really like old English engines. It's difficult trying to explain things to non-experts.

Around here, sloppy talkers use "gas" instead of "gasoline." But an English engine runs on "petrol," and gasoline is not a gas, so I will always say "gasoline" or "petrol."

For us, an "oil" engine runs on kerosene. But oil is also that stuff that you put on your door hinges so they don't squeak. But you can't run your oil engine on that kind of oil. When talking about kerosene, you guys say "paraffin." But paraffin is wax, and you certainly can't run an engine on wax.

And then there are engines that run on "producer gas" or "town gas." That's the stuff that comes to your house in a pipe and makes the fire on your stove where you cook dinner. You guys call that "gas." Everyone here calls it "gas," as well. But like I said earlier, sloppy talking Yanks also use "gas" instead of "gasoline." So you need to listen to the context of the conversation to know what's being said. And yes, I've been known to convert gasoline engines to gas engines.
 

Planemo

E*POWAH Elite
Mar 12, 2021
575
660
Essex UK
I didn't miss anything. The post I was responding to was in relation to Manc44 stating that splines are a 'stupid idea' because they can slip/round off on the shaft. That didn't happen with your snapped shaft, even when an excessive amount of power was sent through it. Enough to snap the shaft and twist the area around the splines. My point is that the splines still didn't let go despite the torture.

Further, you didn't post a pic of the hub that your destroyed shaft was attached to but I highly suspect that the hub splines were also fine.

I spent 15 years tuning 800bhp+ cars. I never saw a stripped spline in a clutch plate, drive shaft or prop shaft.

Seen plenty of snapped shafts.
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,105
4,636
Weymouth
I didn't miss anything. The post I was responding to was in relation to Manc44 stating that splines are a 'stupid idea' because they can slip/round off on the shaft. That didn't happen with your snapped shaft, even when an excessive amount of power was sent through it. Enough to snap the shaft and twist the area around the splines. My point is that the splines still didn't let go despite the torture.

Further, you didn't post a pic of the hub that your destroyed shaft was attached to but I highly suspect that the hub splines were also fine.

I spent 15 years tuning 800bhp+ cars. I never saw a stripped spline in a clutch plate, drive shaft or prop shaft.

Seen plenty of snapped shafts.
you have obviously never owned a VW Transporter T5. Whilst it is a very reliable van it does have one weakness and that is the drivers side driveshaft. It is in 2 parts. A short stub shaft that fits into the gearbox output and a longer main driveshaft that slides into the stub shaft on splines. Typically at over 100k miles the splines on both the stub shaft and main driveshaft joint wear to the point they slip and you loose all drive!!
The reason is that splines on the stub shaft are made of a softer metal than those that fit into the gearbox and so act as a shear point protecting the gearbox output.

In terms of the driveshaft itself shearing ( as in photos a bove) I raced Minis ( offroad). Broken driveshafts were typically caused not by the amount of power transmitted through them but by the suspension compressing more than the CV joint would allow....at which point the driveshaft would be unable to rotate.............net result in a mini at speed would be a spectacular ass over front roll!!
 

Mikerb

E*POWAH Elite World Champion
May 16, 2019
6,105
4,636
Weymouth
Dude! I collect old engines, and I really like old English engines. It's difficult trying to explain things to non-experts.

Around here, sloppy talkers use "gas" instead of "gasoline." But an English engine runs on "petrol," and gasoline is not a gas, so I will always say "gasoline" or "petrol."

For us, an "oil" engine runs on kerosene. But oil is also that stuff that you put on your door hinges so they don't squeak. But you can't run your oil engine on that kind of oil. When talking about kerosene, you guys say "paraffin." But paraffin is wax, and you certainly can't run an engine on wax.

And then there are engines that run on "producer gas" or "town gas." That's the stuff that comes to your house in a pipe and makes the fire on your stove where you cook dinner. You guys call that "gas." Everyone here calls it "gas," as well. But like I said earlier, sloppy talking Yanks also use "gas" instead of "gasoline." So you need to listen to the context of the conversation to know what's being said. And yes, I've been known to convert gasoline engines to gas engines.
........... FYI........the majority ( still) of cars on the roads in the UK run on Diesel......sometimes called DERV........before the advent of high compression turbo diesel engines a derogatory name for the diesel engine was " oil burner"!
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,362
8,588
Lincolnshire, UK
This is why I don't use a Hollowtech 2 crank which is basically what that EP8 looks like to me, with the same shallow looking ridges where it meshes together. I never had a Hollowtech 2 crank slip on me but I can see just from looking at it, there's a good chance it might happen.

STUPID design...

UscUoTc.jpg
They look a bit like splines, but they are not. They are probably made with a splining tool, by the same process that produces proper splines.
Don't forget that the main drive is the from the clamping forces exerted by the two clamp screws. Those ridges provide a rough surface to virtually eliminate the chances of slippage (provided the clamp screws don't come loose!) If there were no clamp screws, those ridges would have to be proper splines that have square edges and transmit drive.
 

R120

Moderator
Subscriber
Apr 13, 2018
7,819
9,185
Surrey
Its an interesting one this, my instant opinion is to blame E13 as in my own personal experience they make some of the worst quality components I have had the displeasure of buying, but at the same time you have to give them the benefit of the doubt.
 

eMullet

Active member
Mar 28, 2021
149
171
Planet Earth
The only spindle fails that I have heard, are wide q-factor in fatbike cranks and the e13 boost. Shimano doesn't make any fatbike cranks. I have hear any fails with Shimano's own cranks.
 

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