Shimano EP8 stops working while riding - no fault in log?

[hctagalong]

Well how’s it going lads any joy in recent weeks? I run a guiding business and now have 2 in the fleet with this problem

I've finally connected with a helpful Canyon technical support rep (I'm in the US) and he has been working with Shimano via the warranty claim process. Shimano thinks the problem is the battery+wiring harness (the wire that runs direct from the drive unit to the battery) and are sending me replacements under warranty.

To be honest, I'm skeptical that this is the culprit, but what do I know -- I'm a rookie with regard to eMTBs. Further, I've already tested with a different battery and it was fine for a few rides then the dreaded power cut happened. I've reviewed my ride data and have the following observations:

• Problem always happens when the temp is 70+ (Fahrenheit); relative humidity doesn't seem to matter
• Never has cut out at the beginning of a ride; always 1+ hr into the ride. I usually start my rides at 100% battery therefore the battery consumption is around +/- 60% when it happens (not the same each time and one time the consumption was only around 45%; an outlier but was fairly warm that day)
• Only occurs at trails and outings when I'm riding a bit more "spirited" (constant motion, pushing the pace, rougher terrain). Ride a little lighter pace with some stops along the way, no power cut.

Given the above this seems like a thermal problem to me but again, Shimano believes it's a battery+wiring harness. I haven't received those yet but should early this week. I'll get them on straight away and try again. The challenge is that it's getting cooler where I live now that summer is winding down and I've not experienced a problem, yet, with cooler temps (I got the bike September 2023 and didn't have any problems until June 2024). For reference, I now have just over 500 miles on it.

I'll let you know what I find after I get a few rides in with the new wiring harness and battery.

 

[Enduromalagaemtbholidays]

Well....bummer. New battery is not the answer. Another ride (using the alternate battery) and unfortunately additional power cut-outs. Again, no faults in the drive unit logs. And, like the other events, it doesn't occur until later in a ride (60%+ of the battery consumed). Only guess I have left is that it's a thermal-related problem.

At this point I have nothing left to try except keep working the warranty process (which has its own challenges that I'm learning about).

Well how’s it going lads any joy in recent weeks? I run a guiding business and now have 2 in the fleet with this problem

I've finally connected with a helpful Canyon technical support rep (I'm in the US) and he has been working with Shimano via the warranty claim process. Shimano thinks the problem is the battery+wiring harness (the wire that runs direct from the drive unit to the battery) and are sending me replacements under warranty.

To be honest, I'm skeptical that this is the culprit, but what do I know -- I'm a rookie with regard to eMTBs. Further, I've already tested with a different battery and it was fine for a few rides then the dreaded power cut happened. I've reviewed my ride data and have the following observations:

• Problem always happens when the temp is 70+ (Fahrenheit); relative humidity doesn't seem to matter
• Never has cut out at the beginning of a ride; always 1+ hr into the ride. I usually start my rides at 100% battery therefore the battery consumption is around +/- 60% when it happens (not the same each time and one time the consumption was only around 45%; an outlier but was fairly warm that day)
• Only occurs at trails and outings when I'm riding a bit more "spirited" (constant motion, pushing the pace, rougher terrain). Ride a little lighter pace with some stops along the way, no power cut.

Given the above this seems like a thermal problem to me but again, Shimano believes it's a battery+wiring harness. I haven't received those yet but should early this week. I'll get them on straight away and try again. The challenge is that it's getting cooler where I live now that summer is winding down and I've not experienced a problem, yet, with cooler temps (I got the bike September 2023 and didn't have any problems until June 2024). For reference, I now have just over 500 miles on it.

I'll let you know what I find after I get a few rides in with the new wiring harness and battery.

this is the best narrowing down of this problem I’ve seen on the internet

Ok so, I have one bike (Husqvarna mc4 23) , I believe it’s likely the wiring harness one really brutal day of dh runs on the “sram test track” in mijas Spain (next bike could be thermal ) started out with a silent bike but could hear the battery slowly rattle its loose inside the carbon frame and problems started but manageable also aggravated by the hot Spanish summer 40+ Celsius, Every man, beast and machine is suffering lol

The Other bike a husky mc2 with ep6 motor doing the same when it gets warm cuts of sometimes even on smooth roads, no error log but definitely heat related. I’m noticing across the bikes that if it gets hot enough that it won’t turn back on any given ride from then on it cuts out after roughly 50% battery usage or a good hours worth of abuse, but I haven’t found any info on heat sensors or anything like that yet.

@hctagalong if you ever escaped the winter to southern Europe you deserve a complementary emtb tour some day for that quality of detail in your e-bike experience

 

[Borbea]

I had this on my Husky. It was bad connection between the battery and connection plate in bottom of battery compartment.
Remove the battery unscrew the plate (battery connection) in bottom of battery compartment. Spray some WD40 and dry. Assemble all back.
Also check the power button.

 

[hctagalong]

Minor update:

I received the warrantied wiring harness and battery from Shimano (via Canyon) and haven't had a cutout since replacing both. While I'm near positive that the battery wasn't the problem (recall that I had tried a second one from the original and still had cutouts -- I'm skeptical that 2 batteries would be defective) perhaps it actually was the wiring harness .

When I replaced the wiring harness, there was no apparent damage to the original one; no cuts, kinks or worn through casing. Nothing of note. Both ends of the connection look normal as well -- on the Spectral:ON the wiring harness is simply a cable that connects to the drive unit and battery directly with no fixed plate/retainer/etc.

Is my saga over? I'm hopeful but not totally convinced. I have ~ 100miles on the new battery+wiring harness but none of that was in hot weather or as spirited riding as when I've experienced the cutouts. Now that temps are falling in my area, I doubt I'll see this again until next season if I do at all.

I appreciate the support and suggestions. Should any of you have cutouts, I feel for you and hope you get it sorted out quickly. Shimano is confident that this will address it for me, time will tell.

 

[steve_sordy]

I had an intermittent power loss problem.
Long story short, it turned out that when a new battery was fitted under warranty, they pinched one of the cables going to the display. That was all it took. There was no external sign of damage. The cable cost £7, but getting to it was a problem (on a Focus Jam2 and not designed to come out as a matter of course) and therefore expensive. thankfully it was still under warranty.

 

[Trickfox]

Figured I'd add my story as another data point. Bought a 2023 Canyon Spectral:On with EP801 & 720 battery in May. Experienced the random cutoff issue starting in June. Did a warranty claim with Canyon through an LBS. At first they were going to send a new harness to the LBS, then decided they thought it was the motor. Shimano provided a replacement motor. About a month on the new motor, and the issue started again.
I've mostly ridden in hot weather, so my first assumption was heat. But I've had 100F rides with no issue, and 80F rides with cutouts in the first 10 minutes, before the motor could have gotten too hot.
I usually experience only one or two cutouts over the course of a 15 mile, 2 hour ride. Sometimes I can do a big ride with zero cutouts, and other times I've gotten three on an 8 mile loop.
It also doesn't seem to be related to battery level, vibrations or big hits.
It has never happened while pedaling, only when coasting.
My LBS did say they've heard of the issue and have heard it's a problem with Shimano motors paired to non-Shimano brand batteries. Curious if anyone with a Shimano battery has had the problem.
It's such a mild annoyance, and seems to not have a known fix, so I'm putting off starting another claim. Will keep my eyes on this thread, hoping a solution is found some day.

 

[ramirez.jon]

Did you guys get any error codes?

My Santa Cruz heckler is having this same issue and splaying E020!
. LBS had had my bike for 3 weeks now and are waiting for a new wiring harness to see if that is the issue.

 

[hctagalong]

Did you guys get any error codes?

My Santa Cruz heckler is having this same issue and splaying E020!
. LBS had had my bike for 3 weeks now and are waiting for a new wiring harness to see if that is the issue.

Nope. In my case there were no associated error codes. If the E020 was related to your issues, consider yourself lucky to at least have something to dig into with regard to triage.

In my case, I received a new wiring harness and battery. It was fine for a little while but then started acting up again for no particular reason that I'm aware of (and no, no error codes, either). Since then, Canyon Spectral:ON owners have been under a "stop ride" notice related to some battery problems. Further, I'm in a cold climate in the US so my outdoor riding season is paused anyhow. Because of the stop ride, you probably won't see too many Canyon owners posting about problems.

Hopefully your LBS will get this sorted out for you! Personally I think this is a big annoyance and would be thrilled to find a solution. To date, I haven't heard of one. Good luck to you!

 

[Trickfox]

No error codes for me either.

I can add another follow up. Per my last post, LBS initially replaced the motor, but I started experiencing the cutout issue again shortly after. Then one day the bike just would not turn back on at all! This time they said it needed a new harness, and I waited nearly 2 months for one because Shimano said it was on backorder. New harness installed, and I have not had a cutout since, which has been about two months.

 

[Trickfox]

No error codes for me either.

I can add another follow up. Per my last post, LBS initially replaced the motor, but I started experiencing the cutout issue again shortly after. Then one day the bike just would not turn back on at all! This time they said it needed a new harness, and I waited nearly 2 months for one because Shimano said it was on backorder. New harness installed, and I have not had a cutout since, which has been about two months.

Another follow up, a couple of months with the new harness and I've started getting the cutouts again I have two friends with the same bike experiencing cutouts as well. We're starting to think it's sensor related, as it only happens when we stop pedaling, and it might even be related to slight back pedaling.

 

[hctagalong]

Another follow up, a couple of months with the new harness and I've started getting the cutouts again I have two friends with the same bike experiencing cutouts as well. We're starting to think it's sensor related, as it only happens when we stop pedaling, and it might even be related to slight back pedaling.

Dang -- bummer to hear that. Frustrating. I've read elsewhere that the problem could be related to the speed sensor. In that thread, it was asserted that there was a small cut in the wire leading to it. When it got wet, that caused problems.

Prior to my getting rid of the bike, I continued to experience this problem even after battery replacements (yes, multiple) and wiring harness replacement. The problem happened in warm weather and cold weather, dry and wet conditions. The best advice I had seen was to verify connections for every wire and inspect for kinks/bends/cuts along all wires. I didn't find anything in my case that was obvious, hopefully you'll find something actionable.

The only common thing I had observed was that the cutouts usually didn't happen until the battery was at 60% or less (meaning that it rarely, if ever, occurred at the beginning of a ride) and the ruggedness of the trail seemed to have played a factor (which could be coincidence where all but 1 ride with cutouts was on a very rocky/rooty trail vs. only 1 ride with cutouts on a fast/smooth/flowy trail). While I doubt the trail had anything to do with it, that could have had something to do with cadence as you suggested where there was more start/stop + back pedaling. Ultimately, I gave up and ditched the bike (it was a Canyon Spectral:ON) because of the cutout issues and because of the ongoing battery recall saga. Hope you find a solution.

 

[Trickfox]

Dang -- bummer to hear that. Frustrating. I've read elsewhere that the problem could be related to the speed sensor. In that thread, it was asserted that there was a small cut in the wire leading to it. When it got wet, that caused problems.

Prior to my getting rid of the bike, I continued to experience this problem even after battery replacements (yes, multiple) and wiring harness replacement. The problem happened in warm weather and cold weather, dry and wet conditions. The best advice I had seen was to verify connections for every wire and inspect for kinks/bends/cuts along all wires. I didn't find anything in my case that was obvious, hopefully you'll find something actionable.

The only common thing I had observed was that the cutouts usually didn't happen until the battery was at 60% or less (meaning that it rarely, if ever, occurred at the beginning of a ride) and the ruggedness of the trail seemed to have played a factor (which could be coincidence where all but 1 ride with cutouts was on a very rocky/rooty trail vs. only 1 ride with cutouts on a fast/smooth/flowy trail). While I doubt the trail had anything to do with it, that could have had something to do with cadence as you suggested where there was more start/stop + back pedaling. Ultimately, I gave up and ditched the bike (it was a Canyon Spectral:ON) because of the cutout issues and because of the ongoing battery recall saga. Hope you find a solution.

One more piece of data, a buddy's Spectral:ON died on the trail one day (would not turn back on), just like mine. At home he pulled the motor cover and unplugged everything, plugged it back in and it booted up after that. Took it to LBS who called Shimano who said to just do a reset. His bike's been working since, but he does get the random cutouts still. But if it ever dies on me miles from the car, at least now I know I can try disconnecting things at the motor to see if it'll come back alive.
Canyon is supposed to ship new batteries in March. Once I get that, I'll reach out to them for the third time to see if they have any more insight into this issue. As common as it seems, surely they should have figured it out by now.

 

[Jamie78]

Another follow up, a couple of months with the new harness and I've started getting the cutouts again I have two friends with the same bike experiencing cutouts as well. We're starting to think it's sensor related, as it only happens when we stop pedaling, and it might even be related to slight back pedaling.

Is this on a 2024 heckler? Mine is doing the same thing

 

[Jamie78]

Did you guys get any error codes?

My Santa Cruz heckler is having this same issue and splaying E020!
. LBS had had my bike for 3 weeks now and are waiting for a new wiring harness to see if that is the issue.

Are you still having issues? I’m having the same issue. I’m considering small claims court.

 

[hctagalong]

Are you still having issues? I’m having the same issue. I’m considering small claims court.

I'm not; but that is because I finally just returned the bike to Canyon (it was a Spectral:ON). That problem and the stop-ride battery recall had finally forced my hand to move on. Hopefully you'll find a solution as that's a pretty frustrating problem.

 

[BikeBarian]

Ok, so I'm another victim of this problem. Mondraker Dusk R with EP801 and Simplo 720Wh battery. Had two cut outs today. It never happened before. Done 1200Km on it in less than a year. I also recently had a speed sensor fault - it died just like that. Rplaced it, went for a ride yesterday withput any issues and another ride today and boom, two cut outs. I don't think this is a battery harness problem as Mondraker did a great job fixing in place battery (battery is not removable) and retention mechanism is solid as rock. No chance for a slight play. It is either smth related to speed sensor or maybe cable loose but such issue like system going off sudenly occurs when engine is loosing it's power from battery. I'm riding with extender and once I forgot to turn off system before unplugging extender - when I unpluged it when system was on it simply went off dark everywhere (remote control, display) - random cut off resemble simillar behaviour.

 

[patdam]

i haved similar problem on my EP801 at my last exit, motor/display several shortly shut off/shut on. that was only the connector HMI/motor wire inefficiently inserted (or constraint on the cable who hadunpluged it ?). pushed until it "cliq" and problem solved

In case of that occur (shut off whithout error message), i recommand to replace firstely the cable between motor and HMI. Mostly if the bike have pivot wiring assembly. On my bike (SCOR) i have only this cable who pass trough the pivot (others on both side of the frame). I have seen that stuck the cable during ride and i have quickly passed it on the frame side hole.

 

[niquep]

Sadly having to add to this subject... I've a Canyon Spectral:ON 2023 bought in July 2023... First issue when I got the bike was that the up/down switch on the handlebars didn't work - this was caused by a pinched cable (it routes under the handlebar grip) - new cable and that issue went away (doesn't say much about Canyons QA in the factory...).

A few weeks later had my next issue when the bike wouldn't turn on - raised a case with Canyon and then using the eTube app was able to coax it back into life.

2024 I had two instances of the bike just dying when out riding - first time I was 30 minutes into the ride going uphill - rough surface and hot weather. Couldn't get it going again so had to ride it back to the car without assistance. By the time I got the bike home it was working again. Next time about a month later it died after about 50 minutes - again hot weather and rough trail. Using the power button I was able to get it going briefly but it then died again after 200 m. Then had to cycle about 9 miles with no assistance back to the car which was not fun. Again by the time I got home the bike was able to be turned on. I assumed both issues were possibly thermal. Certainly couldn't see it was water causing a short as I don't think the bikes been out in the rain for months.

Then Canyon sent the "Do not use" notice in November 2024 - at this point I decided to wait for the new battery before getting the fault investigated... New battery arrived last week. Managed to ride to the top of our village before it died. Again it seemed to fix itself after an hour or so. But now as soon as I connect the battery to the connector in the frame the battery goes into "Battery overcurrent protection" mode (one sold green light, and one flashing) and the bike is completely dead. Take the battery out of the bike and reset it and then charge it and it's fine - as soon it's connected to the bike it gets this issue which sort of leads me to think there's a fault in the wiring harness maybe. I've still got the old battery so will repeat the test with this.

All in I've ridden 360 miles in total on this bike. I've raised a case with Canyon and they just come back with "take it to a dealer" which is what I'll do. I'm close to asking Canyon to take this back under warranty if it can't be fixed soon however. It's a shame as I love the bike and with my 900wh battery it should be great. "Not fit for for purpose" springs to mind.

On the plus side at least my intermittent problem seems to have become permanent which should aid diagnosing the issue.

By way of contrast my previous Spectral:On (2018?) was rock solid and I took it on some horrendously wet and muddy rides - never missed a beat.

I'll keep you posted as the story develops...

 

[Winford]

intermittent power loss problem. For 14 months. ep801 replaced once after 1400 miles, 6000 miles now. 3 battery to motor rosenburger cables have been replaced.

Just got the recalled battery in it and last two rides it has not shut off yet.

Canyon spectral on CF8. feels like it dropped power 2 weeks ago about 20%. then I got the new battery and that increased power 10% so now bike feels underpowered by 10% which may be weaker batteries that came with recall, or my motor is starting to take a dive

 

[a_double]

Another victim here. EP801 on a SC Bullit. I only have 500 miles on it. LBS replaced the lower battery terminal and battery, but still cuts out. I generally ride in boost to knock out rides quickly. Once it comes back on after time and reconnecting wires it would still cutout in my neighborhood streets. Electronic shifting makes it worse cause it usually doesn't come back on while on the trail, thus I lose shifting. It makes getting back to the Trailhead that much tougher. I wish Shimano would fix this for good cause I love this bike but the E function is a headache.

When this first started happening, SC recommended dielectric grease on the battery mount terminals. That worked for a while but here I am with a bike that's dead and no consistent way of bringing it back online.

 

[Abe530]

Hello keeping this thread active with my misfortune problem of my bike now shutting off 5 times while riding in two ride. I hqve the polygon Collosus n8e with the latest ep801 motor battery, display and switch control. I’ve gotten close to 4k km on the bike. When my problem occurred i was in trail mode pedaling up a hill with about 75% battery left. The first occurance on one a bike path in boost mode with 20% battery left. The first time I couldn’t turn the bike on when It went black so I dropped the battery for a reset. That fixed it 3 times. The last two time its shut off on my last ride dropping the battery didn’t work. But when I bump started the bike(in 1st gear sping the wheel backwards getting the cranks to turn) it turned on right away. As I was talking to my buddy I pressed the off button instead of the power mode because i was thinking about that button more. When i did that It didn’t want to switch torque modes from trail to boost even tho it showed on the display it was in both modes. Then it shut off again while flat pedaling/coasting. Did the bump start again started up fine then the torque modes were working like new..

I posted on facebook and got told it might be a connection issue but I don’t suspect that with the ability to bump start and considering Ive ridden about 200 km between each incident. My guess is its a faulty switch in either the battery or the software. It seems like a short circuit tho everything is fine and it starts up just fine 99.9% of the time. I ordered a new switch and hope it fixes the issue

 

[Winford]

Another victim

Battery for sure.

Most of the first gen batteries overheat and or just intermittently shut off mid ride. all my buddies bikes dd it after 1000 miles

The gen2 battery feels weaker but bike has not shut off once yet with new battery

 

[Winford]

I couldn’t turn the bike on

so there are two things happening. The battery has thermal protection, so when this triggers it shuts off while climbing, and sometimes it takes a few minutes or ten minutes to power back on.

So how you can tell-------- unplug the battery cable off the bike, and you should see two leds lit up. top and bottom and one is blinking. That is an error code the battery is spitting out.

A new cable will fix it, for two weeks, the cable is not the problem, but it has less resistance than an older cable so it mirrors a fix, but the real problem are the batteries and the Shimano electronic board/computer built in the battery.

The second part is the shutting off coasting which is what you get after a new battery cable is installed. Cleaning the cable where it attaches to the motor helps lower resistance, for a few rides using rubbing alcohol. No codes will be present on battery if you check for this one.

 

[a_double]

Battery for sure.

Most of the first gen batteries overheat and or just intermittently shut off mid ride. all my buddies bikes dd it after 1000 miles

The gen2 battery feels weaker but bike has not shut off once yet with new battery

Negative. My LBS gave me a brand new battery, after a couple of laps in boost on the hills of my neighborhood, the bike went dark. I disconnected, cleaned, inspected the main terminals of the battery mount and motor and still hasn't come back to life. My LBS is swapping the motor out next.

 

[Winford]

Negative. My LBS gave me a brand new battery, after a couple of laps in boost on the hills of my neighborhood, the bike went dark. I disconnected, cleaned, inspected the main terminals of the battery mount and motor and still hasn't come back to life. My LBS is swapping the motor out next.

Interesting. My motor got swapped out early on. was problem free for a few weeks, then it all came back.

Im sure you tried the old battery to see if it booted back up?

 

[a_double]

Interesting. My motor got swapped out early on. was problem free for a few weeks, then it all came back.

Im sure you tried the old battery to see if it booted back up?

Yes, I tried both. Hopefully the motor swap will do the trick!

 

[Winford]

Hopefully

Right!

I just sent Canyon an email about loss of power. The Shimano service center says without an error code, or bearing noise, they cant touch it

 

[a_double]

My EP801 was swapped but the assist limit is set to 25km/h

What are my options for setting the limit to 32km/h and changing the wheel circumference?

 

[borysgo2]

Right!

I just sent Canyon an email about loss of power. The Shimano service center says without an error code, or bearing noise, they cant touch it

You know what is the easiest way for Shimano ? Release software update to cover up/turn off permanently one or two faults in fault table in SW. No faults - no evidence for a warranty claim. Simple as that
Now the question is - were they already done that ?

 

[Winford]

changing the wheel circumference?

Cannot be done

What are my options for setting the limit to 32km/h

My local shop turning mine up to 20mph pretty cheap