First crash at high speed

[Marcin Small-ski]

What's up guys. Unfortunately my first post on the forum is about my crash, but well never had doubts about my wheel until today.

 

So, yesterday I finally managed to crash my KS 18XL for the first time. That's my first wheel and I loved it to the degree that I used to ride with the top speed of 50 km/h. Thankfully I was not stupid enough to do it without being fully equipped with a full face helmet, wrist, knee, elbow guards and some motocross gloves. Safety first lol.

 

The reason I'm writing here is to understand what actually happened. I was at moderate/high speed somewhere around 40 km/h I guess. I wanted to accelerate so I pushed it pretty heavily on the front. Then I heard like 2-3 beeps and the wheel totally lost the horizontal balance at the very same moment. I landed on my face as you can imagine.

 

My settings are probably dumb for all of you as I had only the last signal turned on (recently changed the voice "please decelerate" to the beeps) and the pedal tilting both set to 50km/h. The battery is 89% charged.

 

Is it correct to think that I was simply very close to the wheel's limit and when I pushed hard to accelerate the wheel just simply couldn't catch up nor stop me? Not to defend my stupidity , but if so isn't it stupid that the wheel actually allows me doing it? Why wouldn't it slow down instead of losing the balance? Second of all even if i had all those alarms set for let's say 40 km/h this can still happen right? For example if the wheel is not fully charged or I'm getting up the hill.

 

I'll try to get the video of the footage as I've noticed there was a camera on the building nearby. I guess I'm pretty lucky that those are the only wounds I have. The wheel is in even better shape as it only has the handle bar a little bit twisted and few scratches.

 

EDIT: The video is available on youtube: https://youtu.be/ctRWwQ-WUss

Edited August 20, 2019 by Marcin Small-ski

[Chriull]

11 minutes ago, Marcin Small-ski said:

The reason I'm writing here is to understand what actually happened. I was at moderate/high speed somewhere around 40 km/h I guess. I wanted to accelerate so I pushed it pretty heavily on the front.

Maximum torque of the ewheels motors (bldc) have a maximum possible torque decreasing with speed.

So accelerating at higher speeds/to higher speeds will lead to overleans.

11 minutes ago, Marcin Small-ski said:

Why wouldn't it slow down instead of losing the balance?

It did slow down relatively to you still pushing forward - thats the reason why you fell. Keeping the pedals straight (balancing) with the rider leaning forward requires the wheel to accelerate.

 

11 minutes ago, Marcin Small-ski said:

Second of all even if i had all those alarms set for let's say 40 km/h this can still happen right?

Yes. It will be harder, but still possible.

11 minutes ago, Marcin Small-ski said:

For example if the wheel is not fully charged or I'm getting up the hill.

Exactly. Going up a hill is for the wheel the same burden as accelerating. Lower battery charge shifts the maximum torque over speed limit to lower values.

So best to keep accelerations softer at higher speeds. Get slower before inclines. Reduce your limits according to the battery charge.

11 minutes ago, Marcin Small-ski said:

I guess I'm pretty lucky that those are the only wounds I have.

Great that nothing more happened especually at these speed!

Ps.: More details in 

 

Edited August 14, 2019 by Chriull

[Jerome]

EUCs require power to stay balance, often more than is required to go fast. Their required power to stay balance s proportionate to the force of the forward or rear leans. The force required is a result of the weight of the rider and the angle of the lean. Power in watts is what the wheel-battery has to supply  to keep you up right and moving at "X' speed down the road. There are two aspects to this required wattage "continuous" and "peak". 

The wheel safety features can handle continuous power and warn you of impending danger/overload. Rapid acceleration from a standstill or while in motion will test the "peak" power capabilities. These "peak power" spikes can be many times greater than the wheel's designed limits even though they might only be a fraction of a second in duration. The wheels at that point will shutdown because, then at least the electronics and battery won't be destroyed.  Tilt-back is the safety feature to force a slowdown. Beeps/warning messages will not likely be perceived and decoded by your brain in  time to correct the problem if the rider causes a "peak power" spike requirement over a certain time duration. 

The kinda short response:  Anyone who rides at or near the wheels maximum speed rating as a matter of fact should be aware that any bump, pothole, object the wheel encounters on the terrain may cause the rider to be thrust-ed violently forward or backwards from which a peak power spike requirement will happen with potentially dire consequences. Anyone who leans forward or backwards at such and angle that puts the wheels continuous power outlay + the peak power outlay over the limits is going down long before they react to any warning signal. A tilt-back "might" save them as the system can initiate it faster than a human can react. In the end, however, it depends on how large if the peak power requirement spike.

 

Edited August 14, 2019 by Jerome

[Unventor]

To me you seem to have been very lucky. Wise move to reflect on why this happened. 

Yes I had accidents too. So I have learned the hard way. But I also knew that one motor to drive speed and maintain the balance on a little surface space is something you shouldn't go to the edge of it design limits. 

My first major crash (you can read about this and my second and third crash, ohh wait I had a forth too here on forum) was at max speed where my wheel lost traction on gravel on asphalt, but I thought I were in control upon the point where the tyre strafe sideways on the gravel. Landed flat on back at 30kmh and slide. Biggest bruise I ever have had in my 46 years at the time. 

No matter how many post we see of these someone always think they can push to the very edge and slightly beyond the limits. At riding at max speed and pushing for hard acceleration spells one thing only, will end badly, no two ways about it. 

That is part reason why keep posting to discourage going max speed and requesting more speed of new designs. 

If you ever drove a car you find that going fast for fun only last so long. Then you mind adapt to the speed, and once this happens the joy of speed is gone, so next thing to happen is to crave for more speed, guess what happens... same thing again and again and.. 

• So this is my point: What people in general seem to enjoy is the forces applied on the body, do acceleration and braking and turning us a better sustainable joy...up to a certain point/speed. The body/mind do however not adapt to change of forces as easy. 

I never gone at max speed of my KS18L because of the above. And I never will do. 

All I can suggest (no intention to sound patronizing) read on the EUC ride dynamic thread, it is long but it holds a lot of insight that should be mandatory info for all riders.

Yet again my early days cost my pain too for my lag of knowledge at the time. 

Note brief ref of my 4 crashes.:

1. Practice emergency breaking from high speed in an enclosure empty parking lot, wheel aquaplaned on gravel at 30kmh/top speed, landed flat on back/buttom. Major bruising lasting 4 weeks
2. Commuting home in rain and darkness a car decided to pass a standstill car in my road lane take my space and ability to avoid a 3" water filled pothole at 15kmh. Hit a finger on landing, but okay after 5min. Like if you get a finger squeeze in a door or so. 
3. Avoiding a oncoming long board rider going in s then S taking my lane too, hitting/clipping a curb at 20-25 kmh, shoulder landing on curb and dislocated. 5 months after still not back to normal, can take another year. Shoulder is at 85% now, 98% of daily normal movement. 
4. Didn't see an tipped over escooter sticking 20cm out on bike lane as I where orienting me of other traffic at big roundabout. Clipped it at 5-10kmh, did superman sliding landing, scrapes on MC suit otherwise unharmed. 

Edited August 15, 2019 by Unventor

[Marty Backe]

Glad you are basically OK. Fortunately luck was on your side, because even with the best protective gear, you can sustain a bad injury.

As others have said, you simply demanded more power from the wheel than it could deliver at the moment.

If you want to play with hard accelerations, do that while stopped or going slow. When you are riding fast you should slowly accelerate. Basically, the faster you go the more gradual all of your actions should be. You should strive to avoid riding over any bumps or divots in your path since then can demand an extraordinary amount of power from the wheel, and if you're already near the maximum power of the wheel, it will stop balancing.

To your question as to why the wheel couldn't slow down; this is impossible. If the wheel were to ever attempt to "slow down", even when you are going walking speed, you would immediately fall off the front of the wheel. This makes sense if you think about how our wheels work. The wheel is always striving to keep it directly under your body's center of gravity. If you lean slightly forward, thereby moving your center-of-gravity slightly forward of the wheel, the wheel will accelerate to keep it under you. It can't slow down. If it did, your center-of-gravity would move in front of the wheel and you would fall off.

So when a wheel is nearing it's maximum speed and/or capability to accelerate, it can either beep at you or attempt to raise the pedals (tilt-back) to give you feedback that you should slow down. But it cannot slow down for reasons explained above. Normally the KingSong wheels will tilt-back to warn you. However, if you attempt to accelerate too fast the wheel does not have enough time to react and warn you, and instead turns off because it has reached maximum speed and/or acceleration.

[Chriull]

10 hours ago, Jerome said:

The wheels at that point will shutdown because, then at least the electronics and battery won't be destroyed.

Nowadays wheels have as hardware protection:

BMS overcurrent cutoff (KS, ?inmotion, ninebot?, not GW). This limit is set as high that it was never reported to be triggered the last years. This was just a problem with the first generation wheels.

Fuses: Gw, Inmotion and ?ninebot? use fuses at the battery line (on the mainboard). They are rarely reported to blow. 

All wheels have some power/current limiting implemented in firmware to limit currents at low speeds. The motor would draw and the batteries would otherwise deliver immense currents vaporizing the wires, connectors and electronics. This mainly protects the wheel while starting (up inclines!), beeing burdened at standstill and for hard braking maneuvers. Does not really work out 100% - as there are still mosfets and fuses blown, cables melting...

Non of this protective measures is a reason for medium to high speed overleans - the only/main reason is the motor generating a voltage proportional to the speed. This reduces the voltage from the battery on the motor, so less maximum current can flow. And less current equals to less torque == less acceleration! So these overleans are just "the nature" of BLDC motors and are not inflicted by any protection cutoff!

[Patton250]

10 hours ago, Unventor said:

To me you seem to have been very lucky. Wise move to reflect on why this happened. 

Yes I had accidents too. So I have learned the hard way. But I also knew that one motor to drive speed and maintain the balance on a little surface space is something you shouldn't go to the edge of it design limits. 

My first major crash (you can read about this and my second and third crash, ohh wait I had a forth too here on forum) was at max speed where my wheel lost traction on gravel on asphalt, but I thought I were in control upon the point where the tyre strafe sideways on the gravel. Landed flat on back at 30kmh and slide. Biggest bruise I ever have had in my 46 years at the time. 

No matter how many post we see of these someone always think they can push to the very edge and slightly beyond the limits. At riding at max speed and pushing for hard acceleration spells one thing only, will end badly, no two ways about it. 

That is part reason why keep posting to discourage going max speed and requesting more speed of new designs. 

If you ever drove a car you find that going fast for fun only last so long. Then you mind adapt to the speed, and once this happens the joy of speed is gone, so next thing to happen is to crave for more speed, guess what happens... same thing again and again and.. 

• So this is my point: What people in general seem to enjoy is the forces applied on the body, do acceleration and braking and turning us a better sustainable joy...up to a certain point/speed. The body/mind do however not adapt to change of forces as easy. 

I never gone at max speed of my KS18L because of the above. And I never will do. 

All I can suggest (no intention to sound patronizing) read on the EUC ride dynamic thread, it is long but it holds a lot of insight that should be mandatory info for all riders.

Yet again my early days cost my pain too for my lag of knowledge at the time. 

Note brief ref of my 4 crashes.:

1. Practice emergency breaking from high speed in an enclosure empty parking lot, wheel aquaplaned on gravel at 30kmh/top speed, landed flat on back/buttom. Major bruising lasting 4 weeks
2. Commuting home in rain and darkness a car decided to pass a standstill car in my road lane take my space and ability to avoid a 3" water filled pothole at 15kmh. Hit a finger on landing, but okay after 5min. Like if you get a finger squeeze in a door or so. 
3. Avoiding a oncoming long board rider going in s then S taking my lane too, hitting/clipping a curb at 20-25 kmh, shoulder landing on curb and dislocated. 5 months after still not back to normal, can take another year. Shoulder is at 85% now, 98% of daily normal movement. 
4. Didn't see an tipped over escooter sticking 20cm out on bike lane as I where orienting me of other traffic at big roundabout. Clipped it at 5-10kmh, did superman sliding landing, scrapes on MC suit otherwise unharmed. 

 That was an awesome analogy comparing it to a car. How many of us take our cars to the extreme speed it can go every day and keep it there at that speed while we are driving? Those of us who have fast cars might do that once or twice just out of curiosity to see how fast it will go but it most certainly isn’t the norm and it would probably destroy the car as it’s not designed for that. I suspect these wheels are not designed to run at its maximum speed the majority of the time it’s running. 

[ir_fuel]

Not going to repeat what has been written here, but I see a worrying trend. People new to this means of transportation tend to push the limits without knowing what they do, and then they crash.

This has always been happening (I am also guilty of this) but back in time wheels had a max speed of 25km/h. Then it started happening on wheels that could go up to 30 km/h.

These days it's happening at 50km/h.

 

I fear the day that a similar type of rider gets their hands on a wheel that has a vmax of 70km/h (this is where we are heading, no doubt about it, with 126V announcements etc). They won't be posting their story here. Pretty sure. All the safety gear in the world won't help you as at those speeds chances of hitting deadly obstacles become bigger and bigger (I don't want to slam my back or my head in a curb while sliding at 60km/h, even with helmet and back protector).

 

We're slowly moving into motorcycle territory, whereby not understanding the machine 100% and just going "flat out" will lead to extremely bad injuries and death. From that point of view, limiting very powerful wheels to a certain top speed until a certain mileage has been reached for beginners might not seems such a bad idea after all. I don't see any other solution to this. People can and should be able to do and buy what they want, but once we start getting some casualties on these high powered euc all of us will be impacted by ridiculous "safety" laws, so that's where one's freedom stops where the other's begin.

 

I don't know if I like this trend ...

[ir_fuel]

25 minutes ago, Patton250 said:

I suspect these wheels are not designed to run at its maximum speed the majority of the time it’s running.

That's not a problem at all. A wheel can drain an entire battery at vmax without suffering, as long as you are on perfectly smooth flat surfaces and have constant weather conditions (no wind you have to push through), and don't weigh 110kg.

The problem begins because people don't do this on one of these:

 

but on a real road, where it's full of unknowns.

[Patton250]

25 minutes ago, ir_fuel said:

That's not a problem at all. A wheel can drain an entire battery at vmax without suffering, as long as you are on perfectly smooth flat surfaces and have constant weather conditions (no wind you have to push through), and don't weigh 110kg.

The problem begins because people don't do this on one of these:

 

but on a real road, where it's full of unknowns.

 I’ve never known of any vehicle that was designed to run at maximum 100% of the time.  Certainly not automobiles or any type of jet planes. How would your TV react if you turn the volume up to maximum left it there 24 hours a day for months on end? I don’t know.  If you say these wheels are designed to do it that’s pretty cool. 

[Chriull]

54 minutes ago, Patton250 said:

I suspect these wheels are not designed to run at its maximum speed the majority of the time it’s running. 

 

27 minutes ago, ir_fuel said:

battery at vmax without suffering, as long as you are on perfectly smooth flat surfaces

Exactly! Running at high speed is quite optimal for the wheels. Perfect efficiency, lower currents,... Just the available torque is very limited - so giod for the wheel, bad for the rider

[ir_fuel]

4 minutes ago, Patton250 said:

 I’ve never known of any vehicle that was designed to run at maximum 100% of the time.

Electric motors are extremely simple and there aren't a lot of moving parts of friction. I think it's even less stressful for the electronics than hard accelerations.

4 minutes ago, Patton250 said:

I don’t know.  If you say these wheels are designed to do it that’s pretty cool. 

It's just a byproduct of their simplicity. Accelerating hard from 0 to 20mph will stress it a lot more than riding at tiltback at a constant speed.

[Marcin Small-ski]

Thanks guys for all the replies. I'm new to the forum and was actually expecting all of you to call me an idiot , but the community seems to be really nice!

I learnt the hard way where the limits of my wheel are and not gonna test that again. I'll definitely slow down till 35-40 and not gonna push that hard for acceleration.

Again, not to defend myself, but I think manufacturers have to do something about it. Don't you think that there should be always a tilt back way before the wheels limits are? I mean if on 50km/h the wheel is at it's 95% power then it's just a matter of time when I crash, while if it had enough power to warn me for like 2s I'd have time to slow down. It's not crystal clear when you buy one of these, without reading this forum. I was actually thinking that if the wheel is designed to ride up to 50km/h, it has to have the power to go like 60-70 that you cannot unlock it for safety reasons. Wishful thinking I know

[ir_fuel]

4 minutes ago, Marcin Small-ski said:

Again, not to defend myself, but I think manufacturers have to do something about it. Don't you think that there should be always a tilt back way before the wheels limits are?

The problem is the wheel's limit is dynamic and depends on a lot of factors. You can be well within its limits and all of the sudden hit a bump in the road that pushes it over its limit.

TBH you could perfectly solve this for your wheel. Use the app and limit your wheel's speed to 15mph. You'll never ever ever ever hit the limit. But is this what you want?

[Unventor]

12 minutes ago, ir_fuel said:

The problem is the wheel's limit is dynamic and depends on a lot of factors. You can be well within its limits and all of the sudden hit a bump in the road that pushes it over its limit.

TBH you could perfectly solve this for your wheel. Use the app and limit your wheel's speed to 15mph. You'll never ever ever ever hit the limit. But is this what you want?

Well I have mine set tilt-back set at 42kmh and slow down message at 40kmh. But these days I hardly go beyond 35kmh. Unless @Mike Sacristan make me do it 

 

21 minutes ago, Marcin Small-ski said:

Thanks guys for all the replies. I'm new to the forum and was actually expecting all of you to call me an idiot , but the community seems to be really nice!

I learnt the hard way where the limits of my wheel are and not gonna test that again. I'll definitely slow down till 35-40 and not gonna push that hard for acceleration.

That would be little point in do this. And like you can see all of us more or less have had same experience.

Speed in itself is not necessary an issue, it is often the push for a hard acceleration that causes major issues and if you get surprised by pothole or others in traffic. 

But what tend to get my reaction is when people state as an aggressive rider which to me translate to not taking into account how others react to them and their style. 

It might be different in other places in the worlds but here (where I live)  taking the cars, is typical for BMW M series model or Audis RS series models.  Some of these drive their car as traffic is a race track (and often not using indicators, so hard to predict their weaving in and out of lanes). This behavior disrupt traffic flow and can easy cause others to have accidents.

When looking at this at our EUCs they are relative fast "small" gadgets that many have little experience in their behavior in the traffic (by others I mean Cars, bikes, pedestrians) so they get unsure or surprised to a very aggressive EUC rider. This then easily leads to dangerous situations. I started to communicate a lot with my hands back this winter, and it seems to work rather well. Like thumb-up or thumb-down or pointing to markings on road or speed bumps. 

 

[ir_fuel]

2 minutes ago, Unventor said:

It might be different in other places in the worlds but here (where I live)  taking the cars, is typical for BMW M series model or Audis RS series models.  Some of these drive their car as traffic is a race track (and often not using indicators, so hard to predict their weaving in and out of lanes). This behavior disrupt traffic flow and can easy cause others to have accidents.

Sweden  

 

[TuN3M@N]

1 hour ago, Marcin Small-ski said:

...

Again, not to defend myself, but I think manufacturers have to do something about it. Don't you think that there should be always a tilt back way before the wheels limits are? I mean if on 50km/h the wheel is at it's 95% power then it's just a matter of time when I crash, while if it had enough power to warn me for like 2s I'd have time to slow down. It's not crystal clear when you buy one of these, without reading this forum. I was actually thinking that if the wheel is designed to ride up to 50km/h, it has to have the power to go like 60-70 that you cannot unlock it for safety reasons. Wishful thinking I know

I also had to learn it the hard way.... BUT

It is simply not possible to protect the rider if he is massiv overleaning the wheel. For this you have to hold back 40-50% overall power. Is´s the system of EUC if you misuse it there is no safety net which will catch you. The problem with overlean is, the wheel needs a huge amount additional power to kick you back, but if you are riding near the maximum current limit there is nothing left. So if the rider is not stopping to force the wheel to go faster by leaning forward he will chrash.

In my case i use an alarm on my watch at 60Amps, simply to know not to push harder than this...for Z10 maximum current is 90Amps. So a roughly 30Amps are left, for bumps, wind and a zealous rider

 

 

Edited August 15, 2019 by TuN3M@N

[2 Drinks Behind]

4 hours ago, TuN3M@N said:

In my case i use an alarm on my watch at 60Amps, simply to know not to push harder than this...for Z10 maximum current is 90Amps. So a roughly 30Amps are left, for bumps, wind and a zealous rider

 

 

Would be really curious if you could elaborate on this setup.  I would be interested in doing something similar.

[hal2000]

6 hours ago, Marcin Small-ski said:

Again, not to defend myself, but I think manufacturers have to do something about it. Don't you think that there should be always a tilt back way before the wheels limits are?

Overlean is a killer and in this case you always learn the hard way because when you overlean the tiltback (if the wheel has enough power to apply it) actually works against you. It's like with cars - if you push your car over its limit nothing will help you, be it a TC, ABS, ASR etc.

[ir_fuel]

59 minutes ago, 2 Drinks Behind said:

Would be really curious if you could elaborate on this setup.  I would be interested in doing something similar.

Wheellog on an Android phone  + a pebble watch.

[Marcin Small-ski]

16 hours ago, ir_fuel said:

Wheellog on an Android phone  + a pebble watch.

Does it have to be a pebble watch or any smartwatch will do? Also Wheellog indeed shows amps and allows u to set alarm on it?

[ir_fuel]

11 minutes ago, Marcin Small-ski said:

Does it have to be a pebble watch or any smartwatch will do? Also Wheellog indeed shows amps and allows u to set alarm on it?

Pebble is the most used option and will work 100% sure. Someone on this forum added support for some Garmin watches too.

Yes you can set a max amp alarm and have the pebble vibrate when you hit it.

[2 Drinks Behind]

23 hours ago, ir_fuel said:

Wheellog on an Android phone  + a pebble watch.

I have an iPhone, but it looks like DarknessBot has the same capability to alert at a current threshold.  I haven't had a chance to try it to verify yet though.  No idea if it works with an Apple Watch as I don't currently have one (although might be a good excuse to get one).   Real question is what to set the threshold to for my wheel.  From other reading on the site, I think my wheel's peak amperage would be around 80A with continuous amperage output of 40A, given that it's 4 battery blocks in parallel, so I might start with 40A and see how that goes.

[Marcin Small-ski]

8 hours ago, ir_fuel said:

Pebble is the most used option and will work 100% sure. Someone on this forum added support for some Garmin watches too.

Yes you can set a max amp alarm and have the pebble vibrate when you hit it.

Sorry for getting off the topic, but is any pebble watch working this way? Found a cheap Pebble Time 14 round, wanted to be sure before i buy it.

[ir_fuel]

6 minutes ago, Marcin Small-ski said:

Sorry for getting off the topic, but is any pebble watch working this way? Found a cheap Pebble Time 14 round, wanted to be sure before i buy it.

don't know if anyone here uses a round one. The only ones I have seen here so far are rectangular.