MCM5 sudden acceleration/cut out at 23 or 24 mph

[maltocs]

Yesterday, I got into my worst EUC accident. Somewhere between 23 and 30mph I got a cut-out on the MCM5. Someone was watching over me as even I was wearing shorts, a T-Shirt, and no protective pads or Helmet and did perfect roll fall. I have very minor scrapes on my hands, my elbow looks like pizza, and there is a little road rash on my shoulder. I KNOW, NOT WEARING PROTECTION IS STUPID. I USUALLY DO.

Generally, I rarely break the 20mph marker on the MCM5. I'm usually riding with my son at about 15-17mph. His MTen3 alarm goes off at 18-19mph. I turn off all alarms on mine but will slow down when his alarm goes off. I dropped him off at school, left his MTen3 in front of his classroom and started my ride home. I rode a little faster than I normally do since I was alone. I stopped at a stop sign, accelerated to full speed and experienced my crash. I ride that smooth road regularly. 

I spent that morning riding the Nikola and cruising the asphalt of Griffith Park at about 25mph (after getting kicked off the trails) so I felt a need to go just a tiny bit faster than I normally ride on the MCM5. I couldn't for the life figure out why it cut out, other than I was going a few miles faster than I've ever taken it. The MCM5 is rated to go faster than what I was doing.

I tested it today just to see what the max speed would be by just tilting the wheel on a stand. It seems that as soon as I hit 23 or 24 mph, it quickly ACCELERATES to MAX, which is about 30-34mph, then CUTS OUT. The beeps don't even start until after the sudden acceleration starts. Once the sudden acceleration, there is no slowing down. I tried this test gong forward and reverse with the same results.  During the crash, I had wheel log running, but it was not logging, it showed max speed at 30mph.

I know @Jason McNeil had an issue with an early MCM4 (on another thread) and didn't trust it. Does this issue exist with the MCM5 or do I have a bad unit??

Also, am I even testing it correctly? Here is the video of my test. You can see i'm trying to use micro back and forth tilts to get it to rise one mile at a time. Right when i hit 23, it just takes off then cuts out. I was able to do the same test on the MTen3, i got it all the way to 30mph and slowed it back down without a cut out. 

For the record I LOVE this wheel. I love the way it rides, the way it feels, it is truly a part of me. After riding the Nikola all day, this wheel even felt better. But now I don't want to ride it knowing that if I touch that magic 23mph or 24mph, it will speed up and dump me. 

[Mimir]

What's your tiltback set to? The behavior in the video seems exactly like how tiltback would behave in a situation where the wheel's kept horizontal- it tries to tilt back by going faster, but that doesn't change the angle, so it goes even faster... until you hit the freewheeling cutoff speed.

[Kens]

Ouch! Great job on the perfect California roll! Most of us were not so lucky when that 'oh crap' moment happened..

The first thing comes to my mind was maybe because of battery degradation or unbalance battery? My second thought was maybe because you used to 100v Nikola power?

P.s. Sorry for off topic but I'm curious about you getting kicked out of Griffith Park.. Did the park ranger kicked you out? What the reason? On which road trail?

[Marty Backe]

We've already talked privately, but I wanted to comment on this post for the benefit of others who have an MCM5. I believe you misjudged the capability of the wheel.

I've always considered the MCM5 a ~25-mph wheel with a full battery, at my weight (~180-pounds). I would recommend that people don't go much faster than ~22mph on the MCM5 to maintain a good safety margin. Just as my KS16X has a max speed of 31-mph, I'll never go much faster that ~25mph to maintain the buffer.

So you were riding on the hairy edge and there was a power surge (maybe a slight acceleration lean from you, or bump, etc) that exceeded it's capability to deliver. And you carry more weight that me.

Riding the Nikola probably desensitized you to the limits of the smaller wheel. So I don't think anything is wrong with your MCM5, for whatever that's worth. Someday when you ride it again, either set a 22-mph alarm or enable tilt-back for that speed, and you'll be fine.

Everyone needs to ride a little more conservatively for each of the wheels that they ride. And personally, I like to remind myself of the dictum that speed kills (not literally for us, fortunately), and thus I'm just going to stick with ~25-mph max regardless of how fast my wheel can go.

Hope you physically and emotionally recover quickly.

[stephen]

9 minutes ago, Marty Backe said:

Everyone needs to ride a little more conservatively for each of the wheels that they ride. And personally, I like to remind myself of the dictum that speed kills (not literally for us, fortunately), and thus I'm just going to stick with ~25-mph max regardless of how fast my wheel can go.

I don't know much about the msm5 but i agree with you about the riding safe speeds, i also try keep in the safe speeds but sometimes go above that safe zone but it doesn't last long but I'm still not at the maximum ,i don't think I'd ever ride a tilt back on any top performer wheel , keep safe have fun ,i do like to push my wheel but that's on a track to see what it can do safley then I'm feel more confident when out and about 👍

2 hours ago, maltocs said:

Someone was watching over me as even I was wearing shorts, a T-Shirt, and no protective pads or Helmet and did perfect roll fall. I have very minor scrapes on my hands, my elbow looks like pizza, and there is a little road rash on my shoulder. I KNOW, NOT WEARING PROTECTION IS STUPID. I USUALLY DO.

 

Glad you rolled the fall out reasonably good 👍 I'm sure you'll remember protection next time or be more conservative on speed

Take care guys

[maltocs]

6 hours ago, Mimir said:

What's your tiltback set to? The behavior in the video seems exactly like how tiltback would behave in a situation where the wheel's kept horizontal- it tries to tilt back by going faster, but that doesn't change the angle, so it goes even faster... until you hit the freewheeling cutoff speed.

tiltback was turned off along with both speed alarms. The only beeps I ever hear this thing really is the low battery alarm when it's low. It was at about 80-85% at crash.

5 hours ago, Kens said:

Ouch! Great job on the perfect California roll! Most of us were not so lucky when that 'oh crap' moment happened..

The first thing comes to my mind was maybe because of battery degradation or unbalance battery? My second thought was maybe because you used to 100v Nikola power?

P.s. Sorry for off topic but I'm curious about you getting kicked out of Griffith Park.. Did the park ranger kicked you out? What the reason? On which road trail?

That morning I parked by the merry go round and rode across the skyline trail (far north side). At train town, I went on Oak Canyon Trail next to Griffith Park Dr. I was going super slow due to all the sand on the trail and saw a horse in the distance. I just turned around and went back. I actually rode the paved Mt Hollywood drive up to that "restoration project" structure on top of the hill where the Park Ranger said he was looking for me due to complaints I was on the trails. He told me to stay off anything dirt. He was very nice about it. I didn't want to push it so I just rode paved the rest of the day up to the observatory, down to greek, and but had to take the trails behind the helipad (Beacon Trail) back down to my car. 

5 hours ago, Marty Backe said:

We've already talked privately, but I wanted to comment on this post for the benefit of others who have an MCM5. I believe you misjudged the capability of the wheel.

I've always considered the MCM5 a ~25-mph wheel with a full battery, at my weight (~180-pounds). I would recommend that people don't go much faster than ~22mph on the MCM5 to maintain a good safety margin. Just as my KS16X has a max speed of 31-mph, I'll never go much faster that ~25mph to maintain the buffer.

So you were riding on the hairy edge and there was a power surge (maybe a slight acceleration lean from you, or bump, etc) that exceeded it's capability to deliver. And you carry more weight that me.

Riding the Nikola probably desensitized you to the limits of the smaller wheel. So I don't think anything is wrong with your MCM5, for whatever that's worth. Someday when you ride it again, either set a 22-mph alarm or enable tilt-back for that speed, and you'll be fine.

Everyone needs to ride a little more conservatively for each of the wheels that they ride. And personally, I like to remind myself of the dictum that speed kills (not literally for us, fortunately), and thus I'm just going to stick with ~25-mph max regardless of how fast my wheel can go.

Hope you physically and emotionally recover quickly.

I guess the lesson for me really is to "know my wheel," not "know my Gotway." True, I was riding the Nikola all day and being used to the speeds, probably pushed my MCM5 harder than I ever did. I always assumed I would hear an alarm BEFORE cutout, not after. I always think "respect the beep" thinking I would hear that 3rd alarm that I cannot turn off and it would trigger at 80% of max power depending on battery before cutout. That's what I remember reading on this forum.

4 hours ago, stephen said:

I don't know much about the msm5 but i agree with you about the riding safe speeds, i also try keep in the safe speeds but sometimes go above that safe zone but it doesn't last long but I'm still not at the maximum ,i don't think I'd ever ride a tilt back on any top performer wheel , keep safe have fun ,i do like to push my wheel but that's on a track to see what it can do safley then I'm feel more confident when out and about 👍

Glad you rolled the fall out reasonably good 👍 I'm sure you'll remember protection next time or be more conservative on speed

Take care guys

I think you mean ride at safe speeds FOR THE WHEEL. I'm very comfortable cruising at 25. The crash WAS  on a street I ride very often and am very comfortable with, I just don't usually ride it that fast. It hard to know where the "push the wheel" threshold is when there are no beeps and to find that threshold means cutout. Thanks for the response. 

 

Thanks everyone for the responses. Like I said, I LOVE the way this wheel feels, so natural for me anyways. (I only wish it had a wider tire for when I"m on dirt. I don't want to do the mod, i'll just keep my fingers crossed for the MCM6 specs.)  I WILL set some sort of alarm or tiltback in addition to being extremely cautious, as now I know at least on my wheel, the 3rd alarm is useless and I will just go with safety margins. Every spec or battery vs weight chart I can find on this wheel says it's a 25+ mph wheel, so I'll take those specs like the do with the battery specs, with a grain of salt and rely on actual user reviews. oh, and SAFETY SAFETY SAFETY. The gods have given me my ONE pass, My body made it though the fall fairly well. The next one is on me to HELMET and PAD up.

[Marty Backe]

3 hours ago, maltocs said:

tiltback was turned off along with both speed alarms. The only beeps I ever hear this thing really is the low battery alarm when it's low. It was at about 80-85% at crash.

That morning I parked by the merry go round and rode across the skyline trail (far north side). At train town, I went on Oak Canyon Trail next to Griffith Park Dr. I was going super slow due to all the sand on the trail and saw a horse in the distance. I just turned around and went back. I actually rode the paved Mt Hollywood drive up to that "restoration project" structure on top of the hill where the Park Ranger said he was looking for me due to complaints I was on the trails. He told me to stay off anything dirt. He was very nice about it. I didn't want to push it so I just rode paved the rest of the day up to the observatory, down to greek, and but had to take the trails behind the helipad (Beacon Trail) back down to my car. 

I guess the lesson for me really is to "know my wheel," not "know my Gotway." True, I was riding the Nikola all day and being used to the speeds, probably pushed my MCM5 harder than I ever did. I always assumed I would hear an alarm BEFORE cutout, not after. I always think "respect the beep" thinking I would hear that 3rd alarm that I cannot turn off and it would trigger at 80% of max power depending on battery before cutout. That's what I remember reading on this forum.

I think you mean ride at safe speeds FOR THE WHEEL. I'm very comfortable cruising at 25. The crash WAS  on a street I ride very often and am very comfortable with, I just don't usually ride it that fast. It hard to know where the "push the wheel" threshold is when there are no beeps and to find that threshold means cutout. Thanks for the response. 

 

Thanks everyone for the responses. Like I said, I LOVE the way this wheel feels, so natural for me anyways. (I only wish it had a wider tire for when I"m on dirt. I don't want to do the mod, i'll just keep my fingers crossed for the MCM6 specs.)  I WILL set some sort of alarm or tiltback in addition to being extremely cautious, as now I know at least on my wheel, the 3rd alarm is useless and I will just go with safety margins. Every spec or battery vs weight chart I can find on this wheel says it's a 25+ mph wheel, so I'll take those specs like the do with the battery specs, with a grain of salt and rely on actual user reviews. oh, and SAFETY SAFETY SAFETY. The gods have given me my ONE pass, My body made it though the fall fairly well. The next one is on me to HELMET and PAD up.

Yes, this is probably the best advice.

Here is a video from one of my earliest rides on the MCM5. You can see I was getting the power alarms at ~23mph (but I couldn't hear them). I was at ~60% battery. The max speed decreases at lower battery levels. It's probably only ~25mph at 100% battery.

And here's a speed chart from EWheels. Notice the max speed based on rider weight.

So my take-away early on was that this was certainly a faster wheel than my KS14S (~19mph with the wind on your back), but it was in no way a fast wheel. So I've always used it as a high accelerating wheel for around town, but never a fast wheel.

Hopefully this makes you feel better that nothing is wrong with your MCM5, and that you can ride it in the future with confidence. But stick to the low 20's, max, and below 20 mostly. Use your Nikola for the adrenaline runs.

 

Edited September 27, 2019 by Marty Backe

[Pingouin]

Hello,

Glad you made it out of this fall in one piece !

Like @Marty Backe said, I also think there was nothing wrong with your MCM5. I guess you either didn't have time to or didn't hear the 80% alarm beeps at all. I think on gotways because the tilt back can only be set a a specific speed, it is not a good idea to trust in with your life, because if you set it at 23mph, it'll be good for the first 30% battery, then the limit motor power output speed might be close or under that tilt back speed.

Also as many EUC riders said, the tilt back demands power to lift your pedals so it can also be dangerous in some rare situations.
I rode my MCM5 to 26.8mph full battery and perfect conditions (flat road, nobody around, 20°C T°..), while being very cautious and immediatly decelerating when hearing the beeps. For my weight the safe speed is the speed where I don't hear the beeping, but mostly under 20mph, max 22mph up to 50% battery.
I agree with you @maltocs that the MCM5 is a great EUC, love it too, plus now it's full black in its newer versions !

All EUCs have their limits, on more powerful EUCs it's just a higher limite.

[meepmeepmayer]

21 hours ago, maltocs said:

It seems that as soon as I hit 23 or 24 mph, it quickly ACCELERATES to MAX, which is about 30-34mph, then CUTS OUT.

That's the standard behavior for every Gotway wheel (and probably the others, too). You go too fast for its liking, it speeds up rapidly trying to save you from overleaning and then switches off when that doesn't work. Not sure if that would also produce a tiltback when riding, I only ever tried it in lift tests. Perfectly normal.

21 hours ago, maltocs said:

The beeps don't even start until after the sudden acceleration starts.

Now that is the problem.

Your video'd test is good. Exactly how you do a "lift" test.

The 84V MCM5 has the 100% battery 3rd alarm at 43kph (26.7mph) and it goes down with battery charge. Now if the emergency speedup appears below that speed, that of course is just plain bullshit.

And that seems to be the case with the MCM5? Your video clearly shows the speedup starts at 23mph (37kph) which is way below the 3rd alarm speed (making the alarm ultimately pointless).

Only other explanation is that you somehow have a tiltback enabled that made you go over the emergency speed (which better be higher than the 3rd alarm). Every time I open the Wheellog options menu my wheel beeps and it changes some unknown settings (I know it disables my 2nd speed alarm). Maybe you activated a tiltback this way? Reset your wheel with the oficial app and never ever open the Wheellog options menu (and be equally careful with Darknessbot as it can change settings too).

Edited September 28, 2019 by meepmeepmayer
correction: there's no emergency speedup, that was the tiltback

[ED209]

It took a while for me to understand the MCM5, over leaning from a slight roll would trigger the alarm, due to the small 14 inch diameter. I gradually realised that to accelerate, I had to apply the power gently at the start, and in a way that was very different to the other wheels. The MCM5 can literally accelerate to 25mph in 2 to 3 seconds from a roll, here is my video of it. 

 

I rarely hear the final alarm on mine. 

 

Edited September 27, 2019 by ED209

[maltocs]

With everyone's advice, I did more tests. Turns out, IT WAS THE TILTBACK SETTING. It seemed to be turned ON to the max 36km/hr. I know I was accelerating during the fall, it probably tried to tilt me back by accelerating even more but because i was leaning forward with about 210lbs that day. Instead of tiltback,  all it did was accelerate to a cut out. I find this really disturbing and dangerous! 

On my new test on the stand (about 85% battery), I turned off tilt back. It functioned as it I thought it should. It can get all the way to 34mph with zero load and the beeps coming in at about 25mph.  25mph seems reasonable if zero load cutout is 34mph to be able to slow down manually. 

I suppose tiltback would work if i was accelerating up a hill or accelerating slowly on flats, but on a wheel that accelerates so fast, it would be inevitable that the wheel would try to tilt back and only end up doing another hard acceleration to cutout. From now on, i'm just going to leave the 2nd speed alarm on and turn tilt back OFF. Oh yeah, and again, WEAR MY PROTECTION. I would suggest for everyone else to turn off tilt back as well if you ever want to hear that 3rd alarm!

Thanks very much for everyone's input. 

btw, here are my injuries. and I already know, I got off really lucky.

Edited September 28, 2019 by maltocs

[meepmeepmayer]

I have to correct myself, there's no emergency speedup on Gotways. That must have been the 48kph tiltback still enabled back when I tested it. Just tried it again and the wheel just gets faster regularly, beeping futilely, till it switches off.

[maltocs]

32 minutes ago, meepmeepmayer said:

I have to correct myself, there's no emergency speedup on Gotways. That must have been the 48kph tiltback still enabled back when I tested it. Just tried it again and the wheel just gets faster regularly, beeping futilely, till it switches off.

sorry, not really understanding. what do you mean by emergency speedup? you mean speeding up to tilt back?

[Mrd777]

Love the mcm5. That chart from ewheels seems wrong. My third alarm comes on at 23.5 mph usually with a fairly full battery.. so that’s it ,I don’t go past 24mph. The beauty of this wheel is not top end speed, it’s about off the line acceleration , and cat like agility.  Glad you are ok Moltocs! 

[Marty Backe]

37 minutes ago, Mrd777 said:

Love the mcm5. That chart from ewheels seems wrong. My third alarm comes on at 23.5 mph usually with a fairly full battery.. so that’s it ,I don’t go past 24mph. The beauty of this wheel is not top end speed, it’s about off the line acceleration , and cat like agility.  Glad you are ok Moltocs! 

Yeah, I don't buy that chart either based on my personal experience, which seems to match yours.

[Marty Backe]

2 hours ago, maltocs said:

With everyone's advice, I did more tests. Turns out, IT WAS THE TILTBACK SETTING. It seemed to be turned ON to the max 36km/hr. I know I was accelerating during the fall, it probably tried to tilt me back by accelerating even more but because i was leaning forward with about 210lbs that day. Instead of tiltback,  all it did was accelerate to a cut out. I find this really disturbing and dangerous! 

On my new test on the stand (about 85% battery), I turned off tilt back. It functioned as it I thought it should. It can get all the way to 34mph with zero load and the beeps coming in at about 25mph.  25mph seems reasonable if zero load cutout is 34mph to be able to slow down manually. 

I suppose tiltback would work if i was accelerating up a hill or accelerating slowly on flats, but on a wheel that accelerates so fast, it would be inevitable that the wheel would try to tilt back and only end up doing another hard acceleration to cutout. From now on, i'm just going to leave the 2nd speed alarm on and turn tilt back OFF. Oh yeah, and again, WEAR MY PROTECTION. I would suggest for everyone else to turn off tilt back as well if you ever want to hear that 3rd alarm!

Thanks very much for everyone's input. 

btw, here are my injuries. and I already know, I got off really lucky.

Ouch. I'm still amazed that's all that happened at that speed. Luck was on your side for sure.

Guess you've confirmed some of our suspicions that it's best to leave tilt-back off unless you have it set to a much lower value. Don't depend on it at the higher end of the speed envelop.

[meepmeepmayer]

1 hour ago, maltocs said:

sorry, not really understanding. what do you mean by emergency speedup? you mean speeding up to tilt back?

Never mind. I thought the behavior shown in your video would also happen with tiltback disabled, as the wheel would rapidly spin up above a certain speed. But that isn't the case.

[maltocs]

2 hours ago, Marty Backe said:

Ouch. I'm still amazed that's all that happened at that speed. Luck was on your side for sure.

Guess you've confirmed some of our suspicions that it's best to leave tilt-back off unless you have it set to a much lower value. Don't depend on it at the higher end of the speed envelop.

I think I naturally fall to my strong side, my right side, and I naturally want to roll. I had two other falls early in my EUC days, last summer, where I pretty much did the same. I don't remember any of the actual falls, it always happens so quick. I just look at my pads, injuries, and holes in my shirt to realize what happened. Maybe all those years of red man training actually did me some good. 

[Delmeekc]

Is there a table that shows what the beeps mean on the MCM5, can't seem to find one and would be nice to know.

[meepmeepmayer]

2 hours ago, Delmeekc said:

Is there a table that shows what the beeps mean on the MCM5, can't seem to find one and would be nice to know.

 

[Delmeekc]

Thanks, screen shot and saved.

[chrisjunlee]

Could you post a screenshot of the beep and tiltback settings to use on MCM5? 

[maltocs]

36 minutes ago, chrisjunlee said:

Could you post a screenshot of the beep and tiltback settings to use on MCM5? 

hard to post a screen shot since setting it is only an INPUT and you only get a confirmation with a beep, so the screen shot won't show the actual settings. But just watch that last video, I actually set the alarms and tilt back. On the alarms part, i'm  going to push OPEN ALARMS, then TURN OFF FIRST ALARM (leaving the 2nd one on). The difference should be the 2nd alarm will come even before the 3rd "80% Cut off warning alarm" giving me more of a buffer. 

[alcatraz]

EUCs are mostly tested by skinny chinese people. Use a heavy duty wheel with 4000w peak power if you're heavy.

[Delmeekc]

On the wheellog output file spreadsheet my MCM5 peaks at over 7000w (7kw), definitely enough power.

On the alarms, is it best to set in wheellog or the gotway app , are the settings stored in the wheel or would they change to whats in the wheellog app.