ElectricMotorcycleForum.com

  • March 19, 2024, 08:49:39 AM
  • Welcome, Guest
Please login or register.

Login with username, password and session length
Advanced search  

News:

Electric Motorcycle Forum is live!

Pages: [1] 2

Author Topic: Lurching/jerking issue, as if pumping brakes  (Read 3087 times)

WoadRaider

  • Jr. Member
  • **
  • Posts: 90
    • View Profile
Lurching/jerking issue, as if pumping brakes
« on: September 20, 2016, 03:43:54 AM »

Hi again Everyone, I'm back again with a new/exciting/potentially dangerous issue to solve!

Here's a bit of background on the bike: It was a 2013 11.4ZF S demo model that I bought as new in March (picked it up on the 27th) with 180 miles on it and the monolyth upgrade. About three weeks after I got the bike the battery wouldn't accept a charge; long story short they weren't properly upgrading/installing the charge fuse and CCU when they started doing the monolyth upgrades and as a result some bikes developed physical damage to those components.

I got the bike back on May 31st and to my recollection it was working perfectly. But that was back when I had the closed throttle regenerative braking setting at 100%. I noticed some very minor lurching, or it was really just slight slowing at that point, sometime in June or early July. It only happened if I quickly released the throttle, and almost always while at high speed (so 50mph+) but it didn't happen every time, the issue was very infrequent. I wouldn't have noticed it if the regenerative braking was set high, and other than some testing when I first got the bike I had kept the regen braking settings at 100%. At least until a couple months ago when I decided I preferred coasting to regen braking and figured out how to rig my front brake lever to trigger regen braking before triggering the front brake.

(As a side note; the regen braking feels slightly less powerful than when I first got the bike.)

The unpleasant slowing was occasional and felt like a very slight/smooth engine braking, for less than a second (two at the most), then it would switch to the normal smooth coasting. After a month or two the slowing became more severe (and sometimes created a lurching motion or felt like someone was lightly pumping the brakes) and it really felt like the strong regen braking effect was occasionally being triggered by the quick throttle release, even though I had the closed throttle regenerative braking set to 0%. But it was still infrequent and it didn't scare me or freak me out or even bother me all that much, so all I did was inform Zero of the issue. I hadn't planned to take it in at that time since I use the bike for transportation and it would be inconvenient to travel back and forth from the closest dealer (which I now have to do).

I became slightly concerned that the problem was getting worse when one time the lurching happened without my having closed the throttle (I contacted zero again after that). Then one night (the 28th) after about 20 miles, returning from a 30 mile trip, it began to lurch severely while at high speed (70-80mph?), on the freeway. I was alarmed and didn't have perfect control of the bike, but I managed to get over to the right lane safely and pull over. I actually didn't try to get over right away because I thought the lurching would stop after a second or two, it didn't, it got worse and there was a strange sound I'd never heard before that I now think was coming from the motor (when I was pulled over I wondered if the bike was broken). The bike also seemed to lose power during that incidence, that hasn't happened any other time. I sent Zero the logs and a couple emails detailing what had happened and was able to drive home with only a few instances of the typical lurching.

(Another side note: By this time I had tried setting 1% regen braking and 5% regen braking and I think something like 15% or 30% to see if the minor problem would go away. It didn't go away with the 1% or 5% regen, but either I didn't notice it or it did go away with higher regen; like I've said, it had been happening very infrequently so I don't know for sure. I should try those settings again now that it is happening frequently.)

So after that I resolved to take it to the nearest dealer; zero had recommended checking/adjusting the motor timing and the throttle. Before I brought it to the dealer the lurching had happened once more without closing the throttle and the minor lurching issue may have become slightly more frequent. I brought it in to the dealer on the 13th. The service guy at the dealer said the timing checked out, I don't know if he adjusted it at all. He said he installed an update as well. Since then the problem has become much more frequent and there is significant lurching just about every time it happens, it has also happened several times without closing the throttle, although nothing to the extent of what happened on the 28th. 

The service guy said it has nothing to do with the regen braking (he has ordered a new throttle) and Zero has only recommended the motor timing and throttle fixes. Am I wrong to think this must be the regen braking causing the issue? It really doesn't feel like it could be the throttle; the throttle is consistent and quick to react. Any thoughts/help with regard to diagnosing this issue would be much appreciated. Thanks!
« Last Edit: September 21, 2016, 12:49:57 PM by WoadRaider »
Logged
perspective, use it

WoadRaider

  • Jr. Member
  • **
  • Posts: 90
    • View Profile
Re: Lurching/jerking issue, as if pumping brakes
« Reply #1 on: September 20, 2016, 03:50:25 AM »

Is there any way for me to check the logs?
Logged
perspective, use it

DPsSRnSD

  • Sr. Member
  • ****
  • Posts: 297
    • View Profile
Re: Lurching/jerking issue, as if pumping brakes
« Reply #2 on: September 20, 2016, 05:16:50 AM »

I assume everyone involved has checked the belt for missing teeth? Does it correlate with temperature, or otherwise as an intermittent connection?
Logged
2020 Zero SR/S
Previously: 2016 Zero SR

BrianTRice@gmail.com

  • Unofficial Zero Manual Editor
  • Hero Member
  • *****
  • Posts: 4014
  • Nerdy Adventurer
    • View Profile
    • Personal site
Re: Lurching/jerking issue, as if pumping brakes
« Reply #3 on: September 20, 2016, 05:33:17 AM »

Is there any way for me to check the logs?

Your post is incredibly hard to read. Try adding lines between paragraphs.

This python script is available which can decode logs that your phone app can email to you from the diagnostics page:
https://github.com/KimBurgess/zero-log-parser

If you're not up to it, post the file that the app produces and someone should be able to run it for you and post the text results.
Logged
Current: 2020 DSR, 2012 Suzuki V-Strom
Former: 2016 DSR, 2013 DS

WoadRaider

  • Jr. Member
  • **
  • Posts: 90
    • View Profile
Re: Lurching/jerking issue, as if pumping brakes
« Reply #4 on: September 21, 2016, 12:40:30 PM »

There's actually been a development. Today my bike seemingly randomly decided to switch the Eco/Custom mode closed throttle regenerative braking setting to 100%+? It activated the powerful regen effect that I had grown used to when I first got the bike and believed had lessened; now that I've felt the stronger regeneration again I know I wasn't just imagining things when I got the bike back after it was in the shop longer than I had it. The regen breaking has to have been less powerful since I got the bike back at the end of may because this is more powerful than 100% has been. I checked the app settings and it says the setting is still at 0%... Today also happened to be the first rainy day we've had here since I bought the bike, I wonder if that could be related. This is actually pretty good evidence that I was right about this being a problem with the regenerative braking mechanism/programming.
Your post is incredibly hard to read. Try adding lines between paragraphs.
This python script is available which can decode logs that your phone app can email to you from the diagnostics page:
https://github.com/KimBurgess/zero-log-parser
If you're not up to it, post the file that the app produces and someone should be able to run it for you and post the text results.
Thanks Brian, I'll do both! I think that elongated paragraph is so hard to read because I was so detailed and descriptive. But at least I didn't leave anything out. I considered breaking it up, but it didn't seem natural to break it in any particular place since other than a short description of a previous (likely unrelated) issue the rest is simply a description of one issue. But I'll break it up anyway.
I assume everyone involved has checked the belt for missing teeth? Does it correlate with temperature, or otherwise as an intermittent connection?
I look at the belt every now and again and haven't noticed anything; i'll go check in detail right now. Just checked, belt seems to be in perfect condition. It seems unlikely to me that a problem with the belt would have been this intermittent/rare and had so many symptoms, but I'm no mechanic. There is no temperature correlation. I live in San Diego County so we have pretty temperate/consistent weather, always a little on the hot side where I am. I'm not sure what could possibly be triggering it; I think it's random with regard to human perception. Although it did cross my mind that maybe any time I hit a little bump in the road or the bike slows too quickly it might be triggering the breaking.
Logged
perspective, use it

WoadRaider

  • Jr. Member
  • **
  • Posts: 90
    • View Profile
Re: Lurching/jerking issue, as if pumping brakes
« Reply #5 on: September 21, 2016, 01:02:59 PM »

Here are the logs from the three times I've sent them to Zero, regarding this issue. I think the newest one is first.
Logged
perspective, use it

Richard230

  • Hero Member
  • *****
  • Posts: 9461
    • View Profile
Re: Lurching/jerking issue, as if pumping brakes
« Reply #6 on: September 21, 2016, 08:33:27 PM »

At first I thought you were describing the "glitch" that affected the 2012 Zero models, but now I don't know what to think.  My only experience is that a couple of times, when there was a lot of moisture in the air, such as when riding in dense fog, my bike would loose its "custom" memory and revert to "eco" mode.  But that was easily resolved by reprogramming via smartphone once I returned home and it has only happened twice in 9K + miles.  I can't read logs, so I am no help there.
Logged
Richard's motorcycle collection:  2018 16.6 kWh Zero S, 2009 BMW F650GS, 2020 KTM 390 Duke, 2002 Yamaha FZ1 (FZS1000N) and a 1978 Honda Kick 'N Go Senior.

BrianTRice@gmail.com

  • Unofficial Zero Manual Editor
  • Hero Member
  • *****
  • Posts: 4014
  • Nerdy Adventurer
    • View Profile
    • Personal site
Re: Lurching/jerking issue, as if pumping brakes
« Reply #7 on: September 22, 2016, 01:04:38 AM »

(Thanks for splitting up the text! Now I understand it.)

It definitely sounds like the drive mode is getting switched or reset somehow. The idea that the app could correct this is particularly baffling.

I would suggest tentatively that you could open up the right handlebar switch assembly and check the connections and apply some electrical insulating (dielectric) grease. Definitely look for moisture.

If that doesn't solve it, you'd have to check around the MBB or something. Again, check for watertightness and apply insulating grease. Opening the enclosure for the board is risky, because it could exacerbate this problem easily, and at that point you may be violating warrantee requirements, so at that point I'd just bring it in to the dealer with this explanation and ask them to check.
Logged
Current: 2020 DSR, 2012 Suzuki V-Strom
Former: 2016 DSR, 2013 DS

WoadRaider

  • Jr. Member
  • **
  • Posts: 90
    • View Profile
Re: Lurching/jerking issue, as if pumping brakes
« Reply #8 on: September 22, 2016, 03:58:28 AM »

At first I thought you were describing the "glitch" that affected the 2012 Zero models, but now I don't know what to think.  My only experience is that a couple of times, when there was a lot of moisture in the air, such as when riding in dense fog, my bike would loose its "custom" memory and revert to "eco" mode.  But that was easily resolved by reprogramming via smartphone once I returned home and it has only happened twice in 9K + miles.  I can't read logs, so I am no help there.
Hey Richard, thanks for taking the time to think about this. Moisture in the air could be the cause of yesterday's issue, in which case it would likely be separate/unrelated to the main issue. Do you remember if your custom settings still showed up in the app or did the actual numbers revert?

It definitely sounds like the drive mode is getting switched or reset somehow. The idea that the app could correct this is particularly baffling.
What idea that the app could correct this? Sorry, I know this amounts to "huh?"

I would suggest tentatively that you could open up the right handlebar switch assembly and check the connections and apply some electrical insulating (dielectric) grease. Definitely look for moisture.
Is that the bundle of wires behind the headlight that go to the components on the right side handlebar and that are protected (other than on the bottom) by a thick laytex-feeling plastic cover?

If that doesn't solve it, you'd have to check around the MBB or something. Again, check for watertightness and apply insulating grease. Opening the enclosure for the board is risky, because it could exacerbate this problem easily, and at that point you may be violating warrantee requirements, so at that point I'd just bring it in to the dealer with this explanation and ask them to check.
I could have them check for water damage, but I can't imagine when, other then yesterday, water damage could have occurred. So that should only be necessary if I can't switch the settings back today.
Thanks for helping.
« Last Edit: September 22, 2016, 04:00:38 AM by WoadRaider »
Logged
perspective, use it

Richard230

  • Hero Member
  • *****
  • Posts: 9461
    • View Profile
Re: Lurching/jerking issue, as if pumping brakes
« Reply #9 on: September 22, 2016, 04:13:55 AM »

Hey Richard, thanks for taking the time to think about this. Moisture in the air could be the cause of yesterday's issue, in which case it would likely be separate/unrelated to the main issue. Do you remember if your custom settings still showed up in the app or did the actual numbers revert?

The custom setting shown in the app had reverted to the original factory settings.  Resetting them was no problem and my custom settings returned when ridden again.  :)
Logged
Richard's motorcycle collection:  2018 16.6 kWh Zero S, 2009 BMW F650GS, 2020 KTM 390 Duke, 2002 Yamaha FZ1 (FZS1000N) and a 1978 Honda Kick 'N Go Senior.

BrianTRice@gmail.com

  • Unofficial Zero Manual Editor
  • Hero Member
  • *****
  • Posts: 4014
  • Nerdy Adventurer
    • View Profile
    • Personal site
Re: Lurching/jerking issue, as if pumping brakes
« Reply #10 on: September 22, 2016, 04:19:22 AM »

It definitely sounds like the drive mode is getting switched or reset somehow. The idea that the app could correct this is particularly baffling.
What idea that the app could correct this? Sorry, I know this amounts to "huh?"

I meant the custom mode settings as Richard guessed.

I would suggest tentatively that you could open up the right handlebar switch assembly and check the connections and apply some electrical insulating (dielectric) grease. Definitely look for moisture.
Is that the bundle of wires behind the headlight that go to the components on the right side handlebar and that are protected (other than on the bottom) by a thick laytex-feeling plastic cover?

You're right to check the wiring behind the headlamp for signs of wear or exposure.

I meant the actual controls bar right next to the throttle where the mode toggle switch is. If moisture got in there or wires were loose and it randomly shorted, it might toggle the riding mode on you while you were riding. And the regen setting on a mode change takes effect immediately, unlike the torque setting.

If that doesn't solve it, you'd have to check around the MBB or something. Again, check for watertightness and apply insulating grease. Opening the enclosure for the board is risky, because it could exacerbate this problem easily, and at that point you may be violating warrantee requirements, so at that point I'd just bring it in to the dealer with this explanation and ask them to check.
I could have them check for water damage, but I can't imagine when, other then yesterday, water damage could have occurred. So that should only be necessary if I can't switch the settings back today.

In my experience, looking doesn't hurt, and no failure is impossible. Some things like this are easily explained by wear on wires or such. Control signals mess up on gas bikes for similar reasons.

My point is that switching the settings back, if it works, might only work temporarily because of a deeper problem that you should do some basic inspection for.
« Last Edit: September 22, 2016, 04:21:21 AM by BrianTRice »
Logged
Current: 2020 DSR, 2012 Suzuki V-Strom
Former: 2016 DSR, 2013 DS

Ndm

  • Sr. Member
  • ****
  • Posts: 295
    • View Profile
Re: Lurching/jerking issue, as if pumping brakes
« Reply #11 on: September 22, 2016, 06:19:05 AM »

The eco/sport switch is on the left side of the headlight on the 2013, I have a similar problem with a slight surge going at a steady pace and the throttle in a fixed position, I move the throttle a little bit and it goes away, I also have twitchy reactions at the" just off closed throttle" position, my guess is that the throttle on either of our bikes is the issue, but my dealer tends to keep the bike for weeks and not resolve any issues, so I can still ride it and I will wait for winter to bring it in, also of note is the fact I have no regeneration on braking regardless of the settings, I'm curious to hear what you find out
Logged
2013 zero S  ZF13.0 , 2017 chevy bolt, 2008 IGO Titan bike

BrianTRice@gmail.com

  • Unofficial Zero Manual Editor
  • Hero Member
  • *****
  • Posts: 4014
  • Nerdy Adventurer
    • View Profile
    • Personal site
Re: Lurching/jerking issue, as if pumping brakes
« Reply #12 on: September 22, 2016, 07:24:19 AM »

Oh, I totally forgot it was 2013, which I also have! Yes, check that switch wiring on the front bracket that hangs out there next to the headlamp, along with wherever it's routed.

I feel silly now, having misunderstood a few things here. :p
Logged
Current: 2020 DSR, 2012 Suzuki V-Strom
Former: 2016 DSR, 2013 DS

kingcharles

  • 1st Empulse E1 owner in NL
  • Sr. Member
  • ****
  • Posts: 325
    • View Profile
Re: Lurching/jerking issue, as if pumping brakes
« Reply #13 on: September 23, 2016, 02:15:11 AM »

Another possibility (not likely but worth a check) is to see if your brake-light activates when you feel the lurching.
Because when your brake sensor is a bit too sensitive it might activate the regen brake while you are cruising and cause the lurch sensation. Perhaps on bumpy roads the rear brake lever is bouncing or with head wind blowing on the front lever?

Logged
Once you go EV, gas is history!

WoadRaider

  • Jr. Member
  • **
  • Posts: 90
    • View Profile
Re: Lurching/jerking issue, as if pumping brakes
« Reply #14 on: September 23, 2016, 04:23:35 AM »

No issues last night (rode for 16 mins) or today (40 mins). So the bike has seemingly, once again, corrected itself; I wonder how long it will last this time, hopefully for good. It's a shame that the strong regenerative braking effect didn't stick around (although I don't think it ever happened with the brake triggered regen anyway, even when I first got the bike).
I didn't try fixing the issue by changing the settings because the bike was working properly and it would be pointless to do so until the lurching is back; as I wouldn't be able to see what effect the settings have. It seems strange to me that moisture would cause such an effect, unless it is an intentional feature; so that any time it rains the bike has max closed throttle regen in Eco mode. Aww man, I just realized I could have tried to use the brake regen with the throttle open, that could have been enlightening. Btw, sport mode seemed normal on the rainy day. Given that it has only happened this one time, in the rain, it seems at least possible that the max regen was triggered by the rain and is mostly or completely unrelated to the primary recurring issue..

The custom setting shown in the app had reverted to the original factory settings.  Resetting them was no problem
Yeah, that probably isn't what happened in my situation because my settings did not revert. The bike just decided it wanted full (or probably stronger) closed throttle regenerative braking instead of 0% closed throttle regen; as I had it set, as the app displayed, and as it was properly executing mid trip before it changed its mind.

I have a similar problem with a slight surge going at a steady pace and the throttle in a fixed position, I move the throttle a little bit and it goes away, I also have twitchy reactions at the" just off closed throttle" position, my guess is that the throttle on either of our bikes is the issue, but my dealer tends to keep the bike for weeks and not resolve any issues, so I can still ride it and I will wait for winter to bring it in, also of note is the fact I have no regeneration on braking regardless of the settings, I'm curious to hear what you find out
I actually remember reading about the slight surge/forward jerk problem on the forum; I remember reading that it is quite common with these bikes? I believe that I've also noticed an occasional, slight, and short speed adjustment while the throttle is held steady. It also happens fairly often when I'm at max speed (set at 64mph for Eco) and the bike is just not compensating completely correctly when trying to maintain speed. I feel like those are just regular quirks of the vehicle operating in an imperfect world and I'm not concerned with them, barely noticeable and don't bother me. 
I haven't heard of the twitchy reactions near the closed throttle position, do you have high/max torque set? But yeah, that sounds like it could be an issue with the throttle. As I've stated before; I can't imagine how my throttle is causing braking unless there are multiple component/programming errors occurring simultaneously. So for example: If the throttle is reading closed when it shouldn't be, or otherwise confusing the MBB, that could be paired with some sort of software oversight, physical component damage, or error which causes the regen to activate at the wrong time.
No braking regen huh? In any mode? I guess it would be kind of hard to tell in sport mode because the regen braking is slight. Have you tried adjusting your brake lever so that it switches on your brake light before activating the standard brake? With that setup you can test if there is any regen braking independent of the front brake. That reminds me; Does anyone happen to know the base settings for Sport mode? And if they are different; for the different models/years? I'll look them up, just more convenient if someone knows.

Another possibility (not likely but worth a check) is to see if your brake-light activates when you feel the lurching.
Because when your brake sensor is a bit too sensitive it might activate the regen brake while you are cruising and cause the lurch sensation. Perhaps on bumpy roads the rear brake lever is bouncing or with head wind blowing on the front lever?
Those are actually really good suggestions, thank you. Unless it starts happening with regularity I have no way to check if the brake light is coming on. I did just check the foot brake lever and it is solid, no way it could be accidentally triggered. The front brake is more loose, I'll see if I can tighten it slightly right now, and if the problem starts happening again I'll try holding the brake lever out to see if it goes away. The main reason as to why I don't think the brake light/sensor being triggered is the cause is that there are long periods where the lurching doesn't present itself. You would think if it's caused purely by the wind or bumpy roads it would happen very regularly and more often if it is particularly windy or bumpy. I have not noticed that to be the case, and like I said in my last post; it has crossed my mind that bumps might be triggering something but it can't be based on the severity of the bumps or solely based on that because there are large bumps that don't trigger it. I live practically out in the country, and while most of the roads are nice there are lots of bumpy roads, and some gravel roads too.

Oh, I totally forgot it was 2013, which I also have! Yes, check that switch wiring on the front bracket that hangs out there next to the headlamp, along with wherever it's routed....it might toggle the riding mode on you while you were riding
Well, if it happens again the next time I drive in the rain/thick fog I'll try greasing them up. But that doesn't seem to have any chance of solving my primary issue, correct? I didn't see any signs of wear, but the contacts are exposed to open air. The mode being toggled doesn't explain the difference in the strength of the regen braking, or could it? I did try using the mode switch and I think I was able to successfully toggle between modes (I think sport was normal, don't remember 100%) but each time I switched back to Eco it had powerful regen. And again, I'm not sure that the mode being toggled by lose or wet wiring could explain the random braking/lurching that is my primary/recurring issue.
« Last Edit: September 25, 2016, 11:39:09 PM by WoadRaider »
Logged
perspective, use it
Pages: [1] 2