Intermittent drops in E7000 assistance

[Drmaestro]

Hi,
I have an ebike with E7000 motor. It generally works quite nicely but I have a somewhat annoying issue. If I ride for 1.5-2 hours (not on exceptionally hilly terrain, I”d say quite a regular ride) and then try to climb a long uphill road, the motor might intermittently cut assistance. It is as if the motor is struggling. It is not a speed cut-off issue, as I am not near those limits when going uphill. Somebody suggested it could be a heating issue with the motor but shouldn’t it give an error on the display?

Also another issue: sometimes when I decrease the assistance level from boost to trail or from trail to eco, I sense a breaking like sensation. I know this is supposed to happen, as you are feeling the weight of the bike but I don’t always feel it. Is it normal?

Thanks

 

[R120]

Check that the wheel sensor magnet is aligned correctly with the pick up on the chain stay

 

[steve_sordy]

I feel no braking-like resistance when shifting down from Boost to Trail or from Trail to Eco, just an increase in the amount I need to provide myself. I know that may sound the same, but it is a sensation that is easier to feel than to describe.

Of more concern is the intermittent assistance cut-out. I have no suggestion to offer othr than that it may be a fault. (The two symptoms may be connected of course).

Before taking the bike back to the LBS, try updating your E-Tube app and then linking to your bike. Let us know how you get on, so that those who may seek a similar fault in the future will find a compete solution here.

 

[Lee Dove]

Are you keeping some load on the pedals (torque) all the time. If you are spinning fast it is easy to have a part of the crank rotation with nearly zero torque. The motor spots this and reduces assistance. The assistance is a torque multiplier not a fixed output. Try a one or two gears up and seeif you get it.

 

[Grobison]

My e7000 has this same intermittent problem. Full Power then power lowered for 5 seconds and then back on etc. My suggestion is that it could be a lack of voltage problem.

It has happened to me 3 times after about 1.5 hours ride. Each occurrence was when I was in boost going up a long steep hill for about 5 minutes using a battery that wasn’t totally full from the start and had only 3 bars left.

Every battery when under load (boost) will decrease in voltage and regain it when the load is removed.

My theory... The voltage under boost may have decrease enough to temporarily affect the motor and force a decrease in power for about 5 seconds which allowed the battery to quickly regain voltage and power only to loose it again and so on causing this intermittent power loss.

So perhaps there’s a voltage sensitive circuit somewhere in our motor.

Greg

 

[Lee Dove]

My e7000 has this same intermittent problem. Full Power then power lowered for 5 seconds and then back on etc. My suggestion is that it could be a lack of voltage problem.

It has happened to me 3 times after about 1.5 hours ride. Each occurrence was when I was in boost going up a long steep hill for about 5 minutes using a battery that wasn’t totally full from the start and had only 3 bars left.

Every battery when under load (boost) will decrease in voltage and regain it when the load is removed.

My theory... The voltage under boost may have decrease enough to temporarily affect the motor and force a decrease in power for about 5 seconds which allowed the battery to quickly regain voltage and power only to loose it again and so on causing this intermittent power loss.

So perhaps there’s a voltage sensitive circuit somewhere in our motor.

Greg

I doubt very much it is an intermittent battery voltage problem. If the motor is overheating you would also get a W010 error.

Have you read my earlier post ?

 

[Drmaestro]

I doubt very much it is an intermittent battery voltage problem. If the motor is overheating you would also get a W010 error.

Have you read my earlier post ?

The zero torque problem is easy to replicate (go on a flat road with a very easy gear) and you also feel that the pedals are spinning too fast. I don't think the problem I've mentioned on the original post (and maybe on Greg's post) is directly related to low torque, as in my case, every time the motor cuts assistance, I am already struggling hard to spin the pedals, so I definitley have a lot of torque. Maybe even too much torque, if there is such a thing. The interesting point in my case is that when the problem happens, all I have to do is to stop pedalling momentarily (maybe a quarter of a second) and the motor picks up from where it left. If it was heat, it should have demonstrated a similar behaviour (and also give an error on screen). If it was low torque, it should also repeat the error instantaneously, as I am not changing any gears at that moment.

I wonder if it is a software problem or a battery problem, as Greg has mentioned.

 

[Grobison]

The zero torque problem is easy to replicate (go on a flat road with a very easy gear) and you also feel that the pedals are spinning too fast. I don't think the problem I've mentioned on the original post (and maybe on Greg's post) is directly related to low torque, as in my case, every time the motor cuts assistance, I am already struggling hard to spin the pedals, so I definitley have a lot of torque. Maybe even too much torque, if there is such a thing. The interesting point in my case is that when the problem happens, all I have to do is to stop pedalling momentarily (maybe a quarter of a second) and the motor picks up from where it left. If it was heat, it should have demonstrated a similar behaviour (and also give an error on screen). If it was low torque, it should also repeat the error instantaneously, as I am not changing any gears at that moment.

I wonder if it is a software problem or a battery problem, as Greg has mentioned.

My feelings also. Mine occurs on very steep long hills and I’m in about 4th gear and applying a reasonable amount of leg work.
- Has only ever occurred with a 50% battery. - No errors show up on display.
Like you, if I stop peddling for a moment I also regain power for a few seconds and then loose power again.
Sounds like we have the same problem
Greg

 

[frazerrobbo]

I noticed something similar the other day. I recent wrote off an E7000 motor in a crash and had to get a replacement one. So on my brand new motor on its maiden voyage I was doing a 5km very steep sustained uphill climb on fireroad in Trail mode/granny gear and about half way up i noticed the motor wasn't quite outputting the same level of assistance it had been at the start of the climb. I felt like my I was hitting a brick wall with the pedaling but was not doing anywhere near the speed cut off. Was probs doing 8km/hr average. It was quite a hot day and so i stopped for about a minute. checked a few things turned off and on again and voila, all working again fine.

I wonder if it was overheating or some kind of voltage drop on a sustained climb or maybe i imagined things but im sure its a real thing.

 

[steve_sordy]

A few extra suggestions here:

Might the max torque be reached and the motor backs off a bit? If I recall correctly, the E7000 motor has 70 Nm peak torque, which is less than some other motors.

Might the 250 Watts average have been reached and the power delivery has to be cut to meet the EU requirement? This is probably less likely because the software should be the same for the E8000 motor.

 

[Gary]

E7000 only has 60nm Steve.

Annoyingly both shimano off road motors reduce assistance somewhere around the 130rpm cadence. This has nothing to do with torque. I guess shimano just think folk with E bikes won't spin cranks very quickly.

Derestriction increases pick up lag and cut out can be less smooth. As are older firmware versions if you downgraded to run Apps. ?

 

[Lee Dove]

E7000 only has 60nm Steve.

Annoyingly both shimano off road motors reduce assistance somewhere around the 130rpm cadence. This has nothing to do with torque. I guess shimano just think folk with E bikes won't spin cranks very quickly.

Derestriction increases pick up lag and cut out can be less smooth. As are older firmware versions if you downgraded to run Apps. ?

Looking at the torque curves (online so only an estimate) all the motors have less than 10nm of torque above 130 rpm. At that revs (520 rpm motor?) it would still be delivering 250+ watts.

 

[Gary]

I used to find it super frustrating. (my max cadence is 240+ rpm though).

 

[Lee Dove]

I used to find it super frustrating. (my max cadence is 240+ rpm though).

Most Pro's aim for 100-120 I think so at 240 is a bit wasteful Maybe try using the gears !

 

[Gary]

Most Pro's aim for 100-120 I think

Try thinking harder.

 

[Lee Dove]

Try thinking harder.

My World From a Bicycle: The Ideal Cadence for Competitive Bicycling

 

[Fivetones]

I used to find it super frustrating. (my max cadence is 240+ rpm though).

Video or that didn't happen. I need a laugh for a Friday Gary.

 

[Gary]

Video or that didn't happen. I need a laugh for a Friday Gary.

video?

I can spin up to 220 all day.. any day on my roadbike in jeans mate. (low gear on the flat).
Reaching 240rpm (peak) is a very fast cadence (anything over 200 is really) and my ability to spin fast is partly natural talent, partly just because I ride bikes so much and partly trained so don't be a prick just because you personally can't spin cranks fast. Spinning super fast does have it's place (acceleration/sprinting and when you've run out of gearing eg. mtb/BMX or downhill on a roadbike)

@Lee Dove
Keep thinking dude...
I mean using your grey matter, not google..

Clue: I'm not talking about "efficiency" or "ideal" cadence.
I'm talking about max (peak) max cadences.
But while riding I will regularly spin to 160 and hold it. (which is something Mr Shimano didn't program the E7000 or E8000 to deal with)

 

[33red]

I think the person mentioning the 250 W might be correct. I rarely feel it but i might say it feels like the assistance is tired just catching his breath. Ounce i tought it was overheating and it was just a safety thing to protect from overheating but respecting legal limitations is likely set at the factory. Nothing to do with speed, more about watts. But i might be wrong, i am just trying to understand. At 3,434 kms my Ebike was never at the shop, i am pretty sure engine, battery etc... are all fine.

 

[Hugh-Jazz]

The E7000 should be able to hold the 250W output for hours at a time. The E8000 does not suffer from the same cut-out that I’ve experienced with the E7000. For me it only happens in BOOST mode when I’ve been going for several minutes. The cut-out is total and is on/off with the assistance. When I drop down to TRAIL I do not get the cut-out and the power delivery seems normal. It could be something with the torque sensing threshold value. I’m surprised the motor does not throw an error when the cut-out occurs. I’ll play with the BOOST assistance settings in STUnlocker to see if it helps or hurts.

 

[Hugh-Jazz]

The E7000 should be able to hold the 250W output for hours at a time. The E8000 does not suffer from the same cut-out that I’ve experienced with the E7000. For me it only happens in BOOST mode when I’ve been going for several minutes. The cut-out is total and is on/off with the assistance. When I drop down to TRAIL I do not get the cut-out and the power delivery seems normal. It could be something with the torque sensing threshold value. I’m surprised the motor does not throw an error when the cut-out occurs. I’ll play with the BOOST assistance settings in STUnlocker to see if it helps or hurts.

I believe I may have found my problem. I don’t think my battery was installed all the way into the power terminals. There is a cable management clip that wasn’t fastened down all the way and the battery was held off a millimeter or two. I’ll do a sustained climb in BOOST today to confirm.

 

[Hugh-Jazz]

I believe I may have found my problem. I don’t think my battery was installed all the way into the power terminals. There is a cable management clip that wasn’t fastened down all the way and the battery was held off a millimeter or two. I’ll do a sustained climb in BOOST today to confirm.

More data on the cut-out today. I rode a long and very steep climb in BOOST and the bike started cutting out most of the way to the top. I changed the mode to TRAIL and is was very weak. I pedaled hard in TRAIL to get up the rest of the climb and the assistance stayed weak. After spinning for a short period of time over the top of the climb the power came back. It seems pretty likely that there is a thermal protection control that is causing this. I’m on the latest rev of the E7000 software. This does not happen with the E8000 motor on the same climb. I’ll see if there are any motor logs I can view with STUnlocker.

 

[R120]

My motor, which is definitely fecked but still rideable, has gone into a kind of limp mode whereby the power in all modes is the same and pretty much like eco - the support cuts in and out, and then it flashes up error codes and you have to restart the bike - happens when you put any sort of real pressure into your pedalling, e.g on a steep uphill. Might be same with yours

 

[Hugh-Jazz]

My motor, which is definitely fecked but still rideable, has gone into a kind of limp mode whereby the power in all modes is the same and pretty much like eco - the support cuts in and out, and then it flashes up error codes and you have to restart the bike - happens when you put any sort of real pressure into your pedalling, e.g on a steep uphill. Might be same with yours

I guess I haven’t stressed it hard enough to get an error code. I get the support cutting in and out, but I back in down into TRAIL pretty quickly. Next time I’ll leave it in BOOST to see if I get an error code. Do you remember what the error code number is? I couldn’t find any logs to view for over-temp events.

I lowered my BOOST assistance down to 200% to see if I can do my steep climb without cut-out.

 

[Hugh-Jazz]

My motor, which is definitely fecked but still rideable, has gone into a kind of limp mode whereby the power in all modes is the same and pretty much like eco - the support cuts in and out, and then it flashes up error codes and you have to restart the bike - happens when you put any sort of real pressure into your pedalling, e.g on a steep uphill. Might be same with yours

The limp home never went away? You could have a motor issue then. Have you tried updating the firmware or performing a reset to factory settings?

 

[R120]

No I know my motor has gone, it’s already booked in at LBS to be sent off to Shimano. Not the first one and probably not the last, just trying to help you by explain what happened to mine.

 

[STATO]

Mine has done this on the last few rides, steep hill in boost, spinning hard to keep speed up and get max assisatance. Has a little wobble and feels like youve knocked it down a level. If you back off cadence (or have too cos its harder!) then it feels really weak. It doesnt cut out completely but does feel like its been throttled. Both rides it was 25+degc (hot for northern england!) and battery below 50%.

 

[Pablofer]

Did someone find a solution for the intermitent drops? I have the same problem with my E7000. It happened with 80% battery and less. The motor starts giving me a drop in assistance till y cut completely. After a minute I can start normally for another 5 minutes.
I think is related with the temperature but the external motor temperature y only warm. It happens in Eco too.

 

[Manpad]

Did someone find a solution for the intermitent drops? I have the same problem with my E7000. It happened with 80% battery and less. The motor starts giving me a drop in assistance till y cut completely. After a minute I can start normally for another 5 minutes.
I think is related with the temperature but the external motor temperature y only warm. It happens in Eco too.

Same issue here and I also wonder about temperature as it's been quite warm lately. I will try to replicate on a cooler occasion and report back.

 

[LoBomber]

Has anyone found a solution? I’ve had this happen to me twice. Happened earlier today. Please help shimano!!!