[one more GOTWAY WARNING] ACM died on a hill (it was bad cabling + high stress, final update pg 16)

[meepmeepmayer]

Surprise update, May 19th: Gotway now uses stronger wiring for the motor cables going from the motor to the connectors. They have been convinced by a dealer. Not sure how much it has to do with this So the problem is extremely unlikely to appear again and can be considered solved. June 23rd: it is a general problem that the wheels can produce higher currents than the cables can take, so melting is inevitable under the right circumstances. See this thread for a more up-to-date discussion (the exact same happened to this guy and me):

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Final update, April 27th: wheel is working again, Ian/Speedyfeet did a great job (and Gotway wasn't bad either)! A bit more results, top of page 16. Don't be afraid to use ACMs/Gotways on steep hills, just don't overdo it and be aware of the limitations of what you can expect your wheel to do (that applies to all wheels, no matter the manufacturer).

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Update #2, April 5th: this issue was a combination of lack of proper cabling (messy cable management + Gotway forgot to put heat sleeves around the various cables, though it is questionable how much that would have changed) and very high, continuous stress on the wheel, which led to the motor cables melting and shorting each other. So don't worry too much about the ACMs or Gotway wheels' safety, this event was more due to an outlier situation (though it does seem some components are too weak in general, and the improvements Gotway did won't fix that, the motor cables melting could happen again - see @Xima Lhotz's pictures page 15) - at least statistically, Gotway wheels are still good (if you're not doing constant steeper inclines).

 --> If you are concerned, open your side panel and see if the cabling looks good and has heat sleeves. That's the best you can do. Photos how it should look are at the top of page 15. <--

Just be aware under continuous heavy load conditions, the wheels (any manufacturers really, but KingSong for example would probably be a bit more trustworthy) might cut out on you, without giving you a warning beforehand (which is the scary part).

Everything is not finished yet, but Ian is in contact with Gotway and this will be fixed one way or another. So far, good customer service from both. More updates when they arrive.

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Update: this issue is not related to the motor connectors at all. I initially believed it to be the connectors because they are a known issue, and the wheel shut off without any warning (like high temperature warning) and failing connectors would do that.

What really happened is the motor cables themselves melted together and shorted. Pictures see page 5. Investigation on further details is ongoing

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Another day (or rather night), another Gotway incident...  WARNING to everyone with a Gotway wheel, ACM, msuper V3, monster, does not matter (I think it's ok to post this in General so everybody sees it).

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So I just did a night mountain ride and my 84V 1300Wh Gotway ACM died on me with no warning.

 

What happened:

I went up a fairly steep mountain (but not extreme, really, an estimated max 20% [update: in hindsight, 15% is probably closer] incline maybe, but constant). It was mostly a hard dirt path, 80kg rider, 60% battery. I went fairly slow and the wheel semed far from its limits (easy acceleration, no warning beeps,...)

After no more than 10 minutes, my ACM went dead mid-ride and I hit the ground (thankfully I wasn't going fast). It simply stopped working, tilted right forward and that was it.

On inspection, there was a burnt stuff smell coming from the wheel (you can still smell it). Pushing the power button, the wheel beeps regularly and the 5 back LEDs all flash red. Even when the wheel is off, it is quite hard hard to turn the tire. The light is working normally (you can switch it to on/off/blinking as usual).

Looks like this might be the well-known motor wires connector issue, but this time it's an ACM, not an msuper V3. Afaik this is the first reported such incident with an ACM. So be careful, all GW models can be affected (assuming it's no other issue). If you have a GW wheel manufactured before March (roughly), you have a problem.

I have not yet opened the wheel for warranty reasons, will have to ask Ian (speedyfeet) what to do first. Quite bummed, I have a dead wheel, scraped knee and my left hand's palm is bruised. This could easily have been worse had I gone faster or been less lucky.

 

What you can learn:

• if you have a GW wheel, don't ignore or wait on definitely fixing the motor connector issue (I'm pretty sure that's the reason) if you might be affected. @Marty Backe siliconed the connectors preemptively, I'm not sure if that's enough (*hint*). Completely new, safe connections are probably best.
• I was aware of what might happen but pushed on, and now I have the mess. Bad decision. Do not think "everything will be fine" just because it was until now, there are no warning signs before a cutout.
• hard gloves/wristguards are your friends. #1 safety clothing!
• there's literally no reason not to wear knee guards. Like your hands (palm/wrist), your knees are what realistically hits the ground in most crashes.
• be careful with higher and constant inclines. I did a 1.5 hour mountain night ride before which wasn't constantly this steep, and everything went perfect and it was quite spookily pleasant In hindsight, no idea how close to disaster I've been

Also:

• F**k Gotway. The wheels are really nicely engineered, but the manufacturing sucks. Well, at least they say they fixed the issue (if it's the motor connectors).
• The best way to carry a 20kg disabled/non-turning wheel is to carry it on your (hunched) back, arms forward and folded around your head, holding the handle behind your neck, like a modern day millstone of (Gotway) shame. Maybe you get the picture It's better than the "like holding a baby" alternative, your arms will die soon.

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I'l sleep on it, possibly burn a GW effigy, and tell you more once I can look at the insides of the ACM. Looking forward to what your interpretation of the events is. Looks like the motor connector issue to me (or maybe it's a new, exciting Gotway quirk?), but I don't know for sure.

 

[dpong]

I keep hearing it, as I try to listen.  Not Gotway.  Not now.  Not yet.  Someday, maybe.  Not yet. 

[meepmeepmayer]

Yep, KS16S and Rockwheel GT16 look like mighty fine alternatives right now...

[Hunka Hunka Burning Love]

Sorry to hear about your accident.  Glad that you escaped with some just minor scrapes, but carrying that wheel must have been arduous.  Hopefully you were not too far away from your car.

I wonder with the burnt smell and the resistance to turning whether it could be a burned out MOSFET rather than a disconnection.  Do you have the 12 MOSFET board?  I think the 6 MOSFET controllers were mostly swapped out?

[meepmeepmayer]

84V ACMs only come with 12 mfets as far as I know.

I was thinking about mainboard failure, but discarded it because the rest (lights) work like normal. Also, should there be no temperature or anything warning for the mfets overheating?

But you might be right. Not sure how to interpret the "locked" tire, I thought it was because of interrupted connections to the battery, you can't get rid of the induction currents so the wheel will brake itself (or something like that). Would a damaged mfet do something similar?

[Hunka Hunka Burning Love]

Yeah dunno.  Could very well be a disconnect, but I don't recall the others mentioning that the motor resists turning when a motor wire disconnects.  Maybe after you hear from Ian, please do post up some photos for a postmortem analysis.  Do the Gotways start beeping or tilting back when their temperatures get too hot on the controller board?  Everyone should ride with a logging program so we can see some data just in case of failure.  @Paco Gorina has a handy app that I think works with Gotway and several other wheels now.

BTW a 20 degree hill is pretty steep!   

 

[meepmeepmayer]

9 minutes ago, Hunka Hunka Burning Love said:

Yeah dunno.  Could very well be a disconnect, but I don't recall the others mentioning that the motor resists turning when a motor wire disconnects.  Maybe after you hear from Ian, please do post up some photos for a postmortem analysis.

Thanks!

9 minutes ago, Hunka Hunka Burning Love said:

Do the Gotways start beeping or tilting back when their temperatures get too hot on the controller board?

I wish I knew. Should't they? In gotsight, dumb to assume that.

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I really hope it's "just" the motor connectors. Just traced the route on Google maps, and it's around 20% average incline. If it's the mosfets, that would make the ACM generally unusable for the kind of mountains I want to do. So there might be wishful thinking in me suspecting the motor connectors.

[OliverH]

Sorry to hear about that issue. This stuff is not engineered and not tested on the bench with maximum loads. PLEV for example likes to see a high voltage/ load test to make sure harness/ motor winding have a enough safety margin that something like this doesn't happen. 

[Marty Backe]

Thanks for the report, and sorry it had to happen to you. Since I have the same wheel (and like hills) I have a strong interest in knowing what happened.

Based on the symptoms I don't think that it's a disconnected cable. The case that I saw first hand exhibited a wheel that was on but the wheel did not balance. But the lights, beeps, app connectivity, etc, worked as expected.

Your symptoms point to a motor failure, which if true, is very rare from what I've seen. And not fixable unfortunately.

• A motor that has shorted will create a strong burnt smell
• The motor will be hard to turn when off

If one of the wires inside the motor came off these would not be the symptoms. That's why I think it was either a short or too much current was flowing thru the coils and they melted.

I fear that the wheel will be a total loss, but certainly it will fall under the warranty since nothing a user can do should cause a motor to fry.

Good luck, and let us know what happens  

[Radislav]

Sad to hear. Nevertheless you are in good health, that's great. 

Afaik, if the wheel is difficult to turn by hand, this is a burnt MOSFET, sorry   Long constant climb says for that too.

Gotway (autocorrect is always trying to replace it with "getaway") beeping chart is here:

It had to emit beep-beep once in 2 seconds if overheats and raise the pedals.

[meepmeepmayer]

edit: beep information corrected

Thanks for your help everybody! What's the best way to contact Ian? FB private message?

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Since I can't sleep, now I can give a better description of what the wheel does:

• The burnt smell was not strong, rather light. Just exactly like some small burnt electronics part would smell. I smelled it a little while carrying the wheel down the road if held in front of face. Now no smell at all.
• Switching on the ACM, it does its usual beep, jerks a bit (like starting to balance) but stops after the first jerk
• It makes 2 long-ish beeps (each about as long as a usual speed warning beep) in short succession
• Followed by 4 short beeps (each as long as the switch on beep) and the 5 LEDs are blinking red (probably 2 short beeps per second)
• Switching on, there's a jerk, then it stops balancing and there's a long beep, immediately followed by 5 short ones
• Then only the LEDs keep blinking red until you switch it off (which it confirms with the regular beep)
• Light can be operated as usual
• I can connect to the wheel with wheellog (GW app, being the crap that it is, decided to be stuck on loading screen independently of the wheel issue). It gives me a believable temperature (of what?) at 23°C and shows the battery at 0%!

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@Hunka Hunka Burning Love Good video. Maybe 15% is a better estimate. The steeper part of the road right at the end of the video looks about similar.

@Marty Backe Yea I was thinking of you (and your connector repair) when it happened. The beginning of your latest Griffith park video, I don't think I've been much steeper than that (maybe a bit). Will definitely get back when I know more.

@Radislav Unless I'm suddenly deaf, it made absolutely no beeps prior to the cut out. Also no tiltback, you surely can't miss that. As far as I remember, pedals were normal until the end.

[Hunka Hunka Burning Love]

I'd say get some sleep and email/call Speedyfeet first thing England time.  I'm sure they will sort everything out for you.  No use thinking too much about it.  If it's a control board or disconnected wire or bad motor Ian will get it fixed for you that's something you can be certain of.

[Marty Backe]

1 hour ago, meepmeepmayer said:

Thanks for your help everybody! What's the best way to contact Ian? FB private message?

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Since I can't sleep, now I can give a better description of what the wheel does:

• The burnt smell was not strong, rather light. Just exactly like some small burnt electronics part would smell. I smelled it a little while carrying the wheel down the road if held in front of face. Now no smell at all.
• Switching on the ACM, it does its usual beep, jerks a bit (like starting to balance) but stops after the first jerk
• It makes 2 long-ish beeps (each about as long as a usual speed warning beep) in short succession
• Followed by 4 short beeps (each as long as the switch on beep) and the 5 LEDs are blinking red (probably 2 short beeps per second)
• Then only the LEDs keep blinking red until you switch it off (which it confirms with the regular beep)
• Light can be operated as usual
• I can connect to the wheel with wheellog (GW app, being the crap that it is, decided to be stuck on loading screen independently of the wheel issue). It gives me a believable temperature (of what?) at 23°C and shows the battery at 0%!

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@Hunka Hunka Burning Love Good video. Maybe 15% is a better estimate. The steeper part of the road right at the end of the video looks about similar.

@Marty Backe Yea I was thinking of you (and your connector repair) when it happened. The beginning of your latest Griffith park video, I don't think I've been much steeper than that (maybe a bit). Will definitely get back when I know more.

@Radislav Unless I'm suddenly deaf, it made absolutely no beeps prior to the cut out. Also no tiltback, you surely can't miss that. As far as I remember, pedals were normal until the end.

I spent some time looking for the post, but I couldn't find it. One of the Gotway reps posted a few months ago a chart that listed what all the possible beeps meant (there were something like 20+ codes). There were many diagnostic beeps. I think it was in the Forum, but there's a possibility it was in the Facebook group. If you find that, it may help.

Ian always responded to my e-mails. Don't post in Facebook if you want a prompt reply. Use e-mail (or the phone).

If it turns out to be a blown mosfet that is certainly disconcerting. We weigh about the same and I take a lot of steep hills. But I will say I don't think I've ever ridden a steep hill for more than a minute or so.

[Pingouin]

Hi !!

I am very sorry to hear about your problem, although I'm glad it was only technical and not physical. It's scares the shit out of me, from what I hear you haven't checked your wires ? I think that opening the side of the EUC to check if the connectors are disconnected doesn't void the warranty, at least it most shops here it doesn't, I would be suprise if speedyfeet says the opposit, as it is a safety issue and speedyfeet is well known for their concern about this matter !

If he tells you you can, I would check if it is "simply" a wire issue or not, I have tested the exact same wheel in the same conditions you described, steepd climbs, moutain riding, more than 2h, the only difference is that I weight less, and I have added some epoxy on the connectors, but I didn't smell anything.

I really "hope" it's the connector issue as it is an easy fix, netherless this kind of thing shouldn't happen on a EUC of this pricing, I have asked Gotway about this conector issue and if my solution was ok, they didn't dear reply, same for distributor of my country, they should start to care more about their customers because luckily this always happened at low speed but imagine this at full speed...

Thank you for your report, I will be looking closely for the conclusion, as I don't want to kill myself on my EUC.

[Eddrush]

5 hours ago, meepmeepmayer said:

Yep, KS16S and Rockwheel GT16 look like mighty fine alternatives right now...

Thanks for heads up, Ian should be able to sort it out, it's unfortunate that I will have to send mine back also as I only unboxed it a few days ago. Funny as you mention it - but I've had my eyes on both those EXACT wheels and it seems the better alternative lol. Keep us all posted!

[Rehab1]

6 hours ago, meepmeepmayer said:

So I just did a night mountain ride and my 84V 1300Wh Gotway ACM died on me with no warning.

Sorry buddy! So glad you did not break anything! Damn this sucks! I have not ridden my ACM 1600 just because of all the Gotway issues! I just do not feel safe! Yes please keep us update! I am tearing into my ACM this weekend as well! I am now regretting my purchase!

[Rehab1]

45 minutes ago, Marty Backe said:

I spent some time looking for the post, but I couldn't find it. One of the Gotway reps posted a few months ago a chart that listed what all the possible beeps meant 

The more I read the more pissed off I become!  Does anyone have any direct contact information for the Gotway reps? We all need to band together as a group and contact them with a rage of dissatisfaction!

[US69]

6 hours ago, meepmeepmayer said:

Looks like this might be the well-known motor wires connector issue, but this time it's an ACM, not an msuper V3. Afaik this is the first reported such incident with an ACM. So be careful, all GW models can be affected (assuming it's no other issue). If you have a GW wheel manufactured before March (roughly), you have a problem.

To be fair here...this was quiet clear and known.....that the failure is on ALL newer GW wheels since release of Msuper V3....perhaps except MCM...as this has not enough power to melt the Connection.

i am very sorry that this was not clear for you, and that you thought it was only the Msuper and so you did not check your Connections on your ACM and learned it the hard way :-(

 

[US69]

4 hours ago, Marty Backe said:

Based on the symptoms I don't think that it's a disconnected cable. The case that I saw first hand exhibited a wheel that was on but the wheel did not balance. But the lights, beeps, app connectivity, etc, worked as expected.

Your symptoms point to a motor failure, which if true, is very rare from what I've seen. And not fixable unfortunately.

• A motor that has shorted will create a strong burnt smell
• The motor will be hard to turn when off

If one of the wires inside the motor came off these would not be the symptoms. That's why I think it was either a short or too much current was flowing thru the coils and they melted.

@meepmeepmayer

Before you have not checked inside the wheel it is hard to guess what is the Problem....

marty is right, with what he is saying......but:

I have also seen a Motor Connection failure, which made 2 of the Motor Connections stuck together, the heat burned the 2 together then and  shorted the wheel!

So it could still be a short because of the Connection failure and not the mosfets.....Or because of a shortened Motor Connections the mosfets burned...or whatever...

Would be one of the first mosfets burn where i heard of....

 

So Take a look.....

[Eddrush]

True to some degree. So far I have only noticed this issue stems from the 84volt units -

*ACM 1300wh/1600wh

*Msuper v3s 1300wh/v3s+ 1600wh,

Monster 1600wh/2400wh owners should take this into consideration as well, and (if under warranty) contact their supplier or make the necessary modifications as Marty did in his tutorial  

 

[Mrd777]

All these problems with Gotway.. I have one on order, (ACM 1300) I'm thinking of canceling it?

[Eddrush]

1 minute ago, Mrd777 said:

All these problems with Gotway.. I have one on order, (ACM 1300) I'm thinking of canceling it?

Tbh I wouldn't blame ya if you did, but you could get them i.e your supplier on the phone ASAP and ask to make the adjustments NOW prior to your units dispatch/post/shipping. Problem solved, no headache like the rest of us! 

[Pingouin]

9 minutes ago, Mrd777 said:

All these problems with Gotway.. I have one on order, (ACM 1300) I'm thinking of canceling it?

I'm thinking of swapping my ACM 1300Wh for the GT16 1036Wh, maybe I'll wait for it to come out, but I'm not risking my life on an EUC that is dangerous even though I do love my ACM. I do not have the right toolsto make a proper solder (imo), I did put epoxy on the connectors, but I'm asking myself "is it going to fail ?" each time I go faster than 25kph, and it's quite frustrating, Gotway service isn't great, and they should get into it, it's unfortunate because the EUC they make are great.

In the end, it's up to you to decide, if you get it I would tell you change the connectors asap don't wait for an accident to occur !

[Mrd777]

I just cancelled, I'm not taking a chance with this nonsense, Gotway has "got" to get their act together.

[Marty Backe]

I think everyone that is cancelling their orders or swearing never to ride a Gotway because of this post should maybe hold off a little, at least until @meepmeepmayer tells us what the failure mechanism is.

When the KingSong's stopped functioning because one of their fuses blows, did people stop buying KingSong's? As far as I know they still use fuses, which I think is a bad design. Incorporating a fuse is a fast and dirty solution to preventing excessive current. Proper engineering can avoid a fuse.

If @Jason McNeil's recent sales numbers (Gotway's, not his) are accurate then there are huge numbers of these wheels out there and it appears that the vast majority are not failing.

I just hate to see people give up on such great performing wheels. But I recognize everyone has their own comfort levels in terms of perceived safety.