Commencal MetaPower - EP8 motor issues

[rb.]

After owning my bike for a few weeks today I was having some motor issues for the first time. When climbing a mellow fireroad the motor/clutch would slip/disengage and the cranks would free spin. When I would come to a complete stop the bike would appear to go right back to normal and I could pedal again. This happened probably a dozen times throughout the day. It would happen at what seemed random, sometimes under a decent amount of torque, sometimes when I was just spinning on flat ground. I rode the full day, but this is a dangerous situation if you are out of the saddle and all of a sudden your crank just slips straight down. Or on the backside of the mountain and you can no longer pedal home.

Has this happened to anyone else yet?

 

[Mteam]

Doesn't sound good, was it definitely the motor and not the freehub in the rear wheel slipping?

 

[Zimmerframe]

When climbing a mellow fireroad the motor/clutch would slip/disengage and the cranks would free spin.

as @Mteam says ....

Your cranks are connected to the chainring, which is connected to the chain, which is connected to the rear cassette, which is connected to the wheel/freehub via the splines, which is connected to the wheel which is connected to the tyre, which sometimes connects with the ground.

If your cranks suddenly span with no resistance, this would suggest something slipping between the chain and the ground portion of your drive.

If the motor clutch was engaged or disengaged your pedals would still be turning the chainring/chain and so on.

The exception to this is the "freewheel" mechanism in the motor which enables you to rotate the cranks backwards without turning the chainring - so this could be screwed. The next highly unlikely option is you've somehow stripped most of the teeth on the spider...

 

[rb.]

It was definitely an issue with the motor. I could ratchet my cranks through full revolutions multiple times under load and not find any issue, with the motor on or off. Then when cruising on a flat road, all of a sudden the cranks would just freespin until I came to a complete stop and reset.

 

[mehukatti]

Your cranks are connected to the chainring

Not directly, but through the motor internal freehub mechanism.

 

[melmark]

Have you messed with any of the settings on the app? Wondering if it is somehow software related?

 

[rb.]

Have you messed with any of the settings on the app? Wondering if it is somehow software related?

No. I connected my bike when I first got it, (and may have done an update?), but haven’t touched anything else.

Still waiting to hear back from Commencal to see what they have to say. My local bike shop has not heard of this issue yet.

 

[Gary]

Your cranks are connected to the chainring, which is connected to the chain, which is connected to the rear cassette, which is connected to the wheel/freehub via the splines, which is connected to the wheel which is connected to the tyre, which sometimes connects with the ground.

and sing along kids... next verse coming up...

 

[Mteam]

It was definitely an issue with the motor. I could ratchet my cranks through full revolutions multiple times under load and not find any issue, with the motor on or off. Then when cruising on a flat road, all of a sudden the cranks would just freespin until I came to a complete stop and reset.

The fact that you had to stop the bike before the problem would be fixed seems to point to an issue with the hub on the rear wheel rather than the motor to me. Ie when still rolling the back wheel is turning so the freehub is ratcheting, when you stop rolling the hub fully engages.

But it is hard to tell from just description of the problem on the Internet.

Keep us updated on what it turns out to be.

 

[ThierryGTLTS]

The fact that you had to stop the bike before the problem would be fixed seems to point to an issue with the hub on the rear wheel rather than the motor to me. Ie when still rolling the back wheel is turning so the freehub is ratcheting, when you stop rolling the hub fully engages.

But it is hard to tell from just description of the problem on the Internet.

Keep us updated on what it turns out to be.

Please, could you try another rear wheel on your bike, ask your LBS if necessary.

If the problem is not solved, the motor is the culprit, otherwise check your freewheel.

Thierry

 

[yorkshire89]

If you can replicate it again you should be able to see where the issue is if you have time to look down.

Chainring/chain rotates with cranks = Freehub
Cranks rotate but chainring/chain doesn't = Motor

 

[rb.]

If you can replicate it again you should be able to see where the issue is if you have time to look down.

Chainring/chain rotates with cranks = Freehub
Cranks rotate but chainring/chain doesn't = Motor

The cranks spin and the chainring is stationary.

The issue is in the motor not the rear wheel. I have these same hubs on 3 different wheelsets and there is no issue with the hub/wheel on my Commencal. The dt Swiss star ratchet freehub is a simple mechanism, and when it breaks it is easy to diagnose/replicate the issue again out on the trail. Today I rode my bike and it acted perfectly normal for 45 minutes of fast paced pedaling, before out of nowhere it happened again and my cranks just spun freely until I came to a stop.

Still no reply from Commencal USA.

edit: thank you for the replies. Keep any ideas you have coming.

 

[yorkshire89]

It sounds like the clutch could be failing? I'm not sure how it works in an ep8 though...

It's going to be a warranty job anyway, hopefully Commencal aren't too slow in getting this fixed for you...

E2A - From Pinkbike article - "A one-way clutch delivers smooth engagement while reducing drag for a natural riding feel. "
Do they use something like this?

One-way roller clutches provide e-bike drive flexibility

Applications in ecological transport and industry are being found for one-way roller clutches from Schaeffler

www.environmentalengineering.org.uk

 

[Zimmerframe]

The cranks spin and the chainring is stationary.

On the bright side, you would seem to be our first EP8 failure ! ? ?

If you don't already, take some heavy duty zip ties with you so you can attach the spider/chainring to the cranks - at least you'll be able to pedal back if it completely fails on you during a ride.

 

[R120]

Can you post up a video? Would help - either way if rotating cranks forward chainring should move with them.

 

[ThierryGTLTS]

On the bright side, you would seem to be our first EP8 failure ! ? ?

If you don't already, take some heavy duty zip ties with you so you can attach the spider/chainring to the cranks - at least you'll be able to pedal back if it completely fails on you during a ride.

Good tip

 

[Zimmerframe]

You can clearly see the problem :

None of the gears or parts touch each other !

@Bearing Man any thoughts .. this could be our first EP8 failure ...

Some zoomed images ..

 

[Bearing Man]

Bearings should be alright, looks like they're made from solid steel Actually looks very similar to the E8000, nice touch that they have added security screws to the internal parts.
I was speaking with the company that manufactures the clutch bearing for the EP8 and I can guarantee that one will not be available to buy

 

[Zimmerframe]

I was speaking with the company that manufactures the clutch bearing for the EP8 and I can guarantee that one will not be available to buy

I'm being super dumb .... so a technical question ..

I'd imagined that the chainring/spider connected to the "crank shaft" via it's own splines and had the equivalent of it's own freewheel/ratchet. I think you can sometimes feel this on say a Bosch - or imagine you do ..

Looking at the pictures it looks like only the torque sensor connects to the shaft via splines.

Which suggests that the "clutch" contacts/releases directly against the crankshaft ... ??????

So it's then locked/closed to the shaft by default ? Therefore, you can pedal with the motor off, otherwise the chainring wouldn't turn when you pedal as there are no splines connecting the shaft to that section which has the spider connected to it. But it has a one way ratchet mechanism in there so when you pedal backwards the chainring doesn't turn ??

From what @rb. is describing, either the "ratchet" ? if there is one in there and it works like that, is disengaging in both directions somehow . Or, the "clutch" isn't engaging the shaft by default ???? If it's a ratchet, is it something like a sticking or dislodged pawl ? If the pawl design is different, is this what the descending rattle is that people hear ? The pawl bouncing around ? Does @rb. just need to nail the crap out of it on a bumpy descent ? "Pawls out" so to speak !

 

[Bearing Man]

The clutch bearing is a ramp roller or jam type bearing that is in the big black steel gear and works by gripping the torque sensor the other end of this gear supports the chainring. This is very similar to the Brose system where drive from the pedals is put through the crankshaft and transmitted to the torque sensor through the splines in the crank, then into the spider via the clutch bearing fitted to the opposite end of the torque sensor.
There is a second clutch bearing inside the smaller black gear that disengages the electric motor. This is a standard clutch bearing, so no pawls, no ratchet mechanism.

 

[nosenada]

My e8000 drive unit had a very similar problem that I equated to the clutch slipping. The cranks would turn and the chainring would remain still or turn very slowly (much slower than the assistance you could hear the drive unit providing). I believe both the e8000 and ep8 have similar clutch mechanisms.

I was able to nurse the motor for two months while Commencal waited for a replacement from Shimano by keeping the assistance low (mostly eco high), immediately stopping pedaling when it started slipping (before the grinding started), and being very gentle with the torque on the pedals when the trail transitioned from up hill to a slight dip. The biggest thing that would cause my motor to slip seemed to be when the clutch would disengage on a slight dips then reengage on the next up. Generally the motor needed to be warm for the problem to start.

I mounted a gopro on my downtube pointed at my cranks to document the issue and sent the video to Commencal. From my gopro video and a shaky iphone video of the chainring not moving they were able to authorize the warranty.

Commencal generally would respond to my emails within one or two business days (although this was not during the holidays).

Hope this information is of some help even though it is not the same motor. Such a bummer to have a problem with a brand new bike.

 

[rb.]

Can you post up a video? Would help - either way if rotating cranks forward chainring should move with them.

Yes,
I can try to get a video on my ride tomorrow (if it happens), but to get it in action I would need a gopro pointed towards the chainring while I'm riding. (Like one user mentioned they did).

Edit: And Commencal has been decent about helping me with questions in the past, so I'm guessing part of the delay is because of the holidays. Or maybe they read my email and don't have any solution because motors are on backorder until March and they're just delaying giving me the bad news.

 

[rb.]

On the bright side, you would seem to be our first EP8 failure ! ? ?

If you don't already, take some heavy duty zip ties with you so you can attach the spider/chainring to the cranks - at least you'll be able to pedal back if it completely fails on you during a ride.

Just added two jumbo zip-ties to my pack. I hope it doesn't come down to that, but I definitely don't want to stop riding my ebike when conditions are perfect like it is right now in Northern Ca.

 

[rb.]

Speak of the devil, just got off the phone with Commencal USA and they said no one at their US center has heard of this problem on any of their bikes yet and he was going to try to get in contact with someone at Shimano and bring up this issue. I'm hoping that the isn't a ton of back and forth between myself, Commencal, and Shimano that delays getting my motor fixed or replaced. Fingers crossed.

 

[Duggan]

Hey this sounds basic and am sure you’ve checked this already but I’ve seen these exact symptoms from a friends new bike just recently.
The rear axle had loosened off enough to allow the cassette to move a few millimetres away from the hub causing the ratchet in the free hub body to disengage. Only happened while climbing under load, worth a look just incase.

 

[Bearing Man]

Hey this sounds basic and am sure you’ve checked this already but I’ve seen these exact symptoms from a friends new bike just recently.
The rear axle had loosened off enough to allow the cassette to move a few millimetres away from the hub causing the ratchet in the free hub body to disengage. Only happened while climbing under load, worth a look just incase.

This is an excellent point! Many times when people bring us their bike with "slipping" issues, it turns out to be the chain jumping the front sprocket or rear cassette, or the rear cassette freewheel mechanism is failing. Definitely worth checking for these issues first, especially if you have just fitted a new chain with a worn sprocket or vice versa.

 

[High Rock Ruti]

Speak of the devil, just got off the phone with Commencal USA and they said no one at their US center has heard of this problem on any of their bikes yet and he was going to try to get in contact with someone at Shimano and bring up this issue. I'm hoping that the isn't a ton of back and forth between myself, Commencal, and Shimano that delays getting my motor fixed or replaced. Fingers crossed.

High Rock Ruti

You're blazing trails in so many ways

Warm Regards Ruti

 

[rb.]

Hey this sounds basic and am sure you’ve checked this already but I’ve seen these exact symptoms from a friends new bike just recently.
The rear axle had loosened off enough to allow the cassette to move a few millimetres away from the hub causing the ratchet in the free hub body to disengage. Only happened while climbing under load, worth a look just incase.

Thank you for the suggestion, but not the issue on my bike. When my issue occurs the cranks spin and the chain, chainring, and cassette are stationary.

And yes, I check my rear axle and derailleur bolt before nearly every ride because they seem to like to come loose.

 

[seamarsh]

Thank you for the suggestion, but not the issue on my bike. When my issue occurs the cranks spin and the chain, chainring, and cassette are stationary.

And yes, I check my rear axle and derailleur bolt before nearly every ride because they seem to like to come loose.

guess you sold the decoy? Sorry about the issues sounds like it’s a warranty swap for sure. Maybe something heat related? Only thing I could think to do would be to downgrade firmware? Probably not worth the hassle.

 

[rb.]

guess you sold the decoy? Sorry about the issues sounds like it’s a warranty swap for sure. Maybe something heat related? Only thing I could think to do would be to downgrade firmware? Probably not worth the hassle.

I sold it to my father, so I could still ride it if I really wanted. This bike is better in every way... when it’s working.

worst case, I also own an enduro and ktm 250xc if the warranty takes forever, so have plenty of other toys to keep me busy on the weekends.