KS 16s first crash

[Seba]

On 8/29/2018 at 5:17 AM, mcsmiley said:

Thoughts?  Thanks in advance.  And wear your safety gear.

It would be a good idea to take a deeper look into the internals - check battery and motor connectors, cabling, fuse socket, control board etc. Another thing worth to consider - to turn voice warnings on, as they may be more descriptive than just beeps. I know that voice warnings may be annoying (famous "Hello King Song"), but in this particular situation they are more helpful, because... beep is a beep. With a voice warning there is a clear difference between "Please decelerate" and "Be caution, overpower" or "Your device is low on battery".

Let's assume there is battery problem (say one cell is dead). Under higher load battery voltage will drop abruptly and significantly, so wheel may start to beep not because of high speed (what you probably expect), but because of dangerously low battery level. Consequently, it may overlean causing you to faceplant. Another cause may be a faulty capacitor (or just a broken leg, cold joint etc.). Similar thing - under load spike there may be a voltage drop...

There may be much more causes, but what I would advise you is to turn on voice warnings. They will give you a distinct informations - you will instantly know if you are over speed limit, or your battery is low or if you are about to overlean...

[Lutalo]

1 hour ago, Seba said:

It would be a good idea to take a deeper look into the internals - check battery and motor connectors, cabling, fuse socket, control board etc. Another thing worth to consider - to turn voice warnings on, as they may be more descriptive than just beeps. I know that voice warnings may be annoying (famous "Hello King Song"), but in this particular situation they are more helpful, because... beep is a beep. With a voice warning there is a clear difference between "Please decelerate" and "Be caution, overpower" or "Your device is low on battery".

Let's assume there is battery problem (say one cell is dead). Under higher load battery voltage will drop abruptly and significantly, so wheel may start to beep not because of high speed (what you probably expect), but because of dangerously low battery level. Consequently, it may overlean causing you to faceplant. Another cause may be a faulty capacitor (or just a broken leg, cold joint etc.). Similar thing - under load spike there may be a voltage drop...

There may be much more causes, but what I would advise you is to turn on voice warnings. They will give you a distinct informations - you will instantly know if you are over speed limit, or your battery is low or if you are about to overlean...

Here, here! I prefer the voice commands over the beeps. A lot of riders find them annoying, but I find them comforting. Especially, because I tend towards riding without the KS app online; I rarely use it. Unless I am testing some specific performance measure, I am not in the habit of obsessing over metrics; I simply like to enjoy the ride. I gauge remaining range from battery level checks when I stop, and I usually only bother with that on new routes. I know the wheel's range capabilities on familiar routes. I ride familiar routes much more frequently than unfamiliar ones; so, my situational awareness is usually high. If something is different, the voice commands inform me with unique verbal warnings about specific stress conditions; low battery, overpowering, speed warning etc. I have grown to rely heavily on the verbals.

[LanghamP]

I thought about this crash when I crashed my S1 today.

My wheel felt just like a cutoff, it stopped but did not turn off, and lay on the ground. When I uprighted it a piece of wood fell off, presumably it jammed between the tire and shell.

Maybe this crash has a something that physically jammed instead of being electrical.

[existensil]

Which train station in Denver? Just to be sure, I should ride my EUC over there and perform some sort of sacrifice to end this curse.

[Smoother]

I realize this is an older thread (new to me though)  .

I have experienced something like this and what it felt like to me was

1. wheel senses too high a speed, ( in my case from the wheel  accelerating over two small ripples in an otherwise smooth surface to keep up)

2. wheel initiates tilt back routine,

3. tilt back routine (at max speed) can be violent, demanding a lot of power to speed ahead of the pilot to tilt him back and not simply tilt him off). 

4. sudden demand for power causes an Amp surge,

5 Amp surge causes a Voltage spike (drop),

6. Voltage spike exceeds power available,

7. wheel looses power and balance.

8. rider face plants.

9 Total time lapsed: 1 second max.

10. ample power available to wheel lying on its side, so nothing seems to be wrong (no smoking gun)

Why this could happen to a 72% 840Wh battery is confusing, but the rider's weight is getting up there and we have no data on terrain rise in the immediate vicinity, or the ambient and battery temps.  Add in the potential bad or unbalanced cell or two as discussed above) and the plot thickens

My Philosophy: Don't ride ANY wheel above 90% of the speed it will tilt back or fall over.  My 16s has 3rd. alarm at 32KPH (35kph max speed quoted my King Song) and I NEVER trigger it, it's just not worth it.  Want to ride at 35kph? get a 40+ kph wheel.  You have to build in your own safety margin if you want to be safe(r)

Edited June 12, 2019 by Smoother
added to point 1.

[hal2000]

I have experienced a similar fall on K16B. Series of beeps, the fall, the wheel on its side turned on, green lights, ready to ride. 16S has slipped away from underneath me a couple of times. Personally, I think that (in my case at least) those incidents were due to the engines not generating enough power for my weight (100 kg plus 20 kg of gear). 

Since I switched to 18L and later to 18XL none of that happened again...

PS

@Lutalo

You mentioned your son's fall. What wheel was he riding? And what weight/height is he/was he then?

[Azze80]

My Crash happened exactly one moth ago during a tiltback on a KS14S. I fell and landed on my right shoulder and broke my collarbone. I am still recovering. The wheel was the best thing for me until I crashed. I would like to know exactly what happened, probably my fault of pushing it to tilt-back but I have done it before without any trouble. I weigh 67kg and the battery was arround 85%.

So if there would be a log somewhere or if one could just test what the problem is would be awesome. I want to continue riding in the future but am uncertain if I can rely on a wheel. My aim was to upgrade to the King Song 16S or bigger but as I said... I don't really trust the wheel like I did before.

I don't think there are places I can leave it here in Sweden to have it checked....

[mrelwood]

48 minutes ago, Azze80 said:

if there would be a log somewhere

Unforunately the wheel doesn’t write any logs, at least not which the user can access. Don’t know if the factory could have such tools though. WheelLog, as it’s name implies, does write logs during riding. And for iOS users the DarknessBot. Too late for that though.

Only thing that can be done now to investigate is to consider the circumstances as closely as possible. We can see if we notice any other red flags than pushing the tilt-back, if you reply with: Wheel age, mileage, charging habits, surface at the crash site, incline, acceleration, how far into tilt-back were you, etc.

57 minutes ago, Azze80 said:

pushing it to tilt-back but I have done it before without any trouble. 

Yes, well... Russian roulette is also harmless, most times. Not comparing, just giving another example where former experience might not matter much. When you ride the tilt-back, you are doing something the firmware is trying to prevent you from doing. The pedal balance is constantly in an unstable state, and the firmware is definitely not optimized for changing conditions in riding surface, battery state, acceleration etc during the tilt-back. None of them should cause a cut-out, over-lean or other crash, but it could be that in your case they did.

I used to ride the tilt-back on my previous wheel, the 16S as well. But absolutely definitely without exception, only when accelerating to the tilt-back extremely slowly, and only on familiar and smooth surfaces with zero incline. And even then only at the very beginning of the tilt-back. Which is why I never experienced the abrupt KingSong tilt-back that many people talk about.

[Smoother]

11 hours ago, mrelwood said:

Yes, well... Russian roulette is also harmless, most times.

12 hours ago, Azze80 said:

My Crash happened exactly one moth ago during a tilt back on a KS14S. I fell and landed on my right shoulder and broke my collarbone. I am still recovering. The wheel was the best thing for me until I crashed. I would like to know exactly what happened, probably my fault of pushing it to tilt-back but I have done it before without any trouble. I weigh 67kg and the battery was around 85%. I don't really trust the wheel like I did before.

I don't think there are places I can leave it here in Sweden to have it checked....

Sorry to hear you got injured, and sorry you have lost your confidence. If you upgrade don't upgade to the 16s, it's too slow for you.  You sound like you like some speed so go up to a 45+kph wheel AND DONT RIDE THE TILT BACK.

As for trusting your wheel; any wheel is a lot more trustworthy if you don't ride it at max speed, (see my personal 90% of max speed rule) stuff like this really does keep you out of hospital.

[Lutalo]

23 hours ago, hal2000 said:

I have experienced a similar fall on K16B. Series of beeps, the fall, the wheel on its side turned on, green lights, ready to ride. 16S has slipped away from underneath me a couple of times. Personally, I think that (in my case at least) those incidents were due to the engines not generating enough power for my weight (100 kg plus 20 kg of gear). 

Since I switched to 18L and later to 18XL none of that happened again...

PS

@Lutalo

You mentioned your son's fall. What wheel was he riding? And what weight/height is he/was he then?

At the time he was riding a KS18AY. 1200 watt motor combined with a 630wh battery; sucky combination by today's standards, but top of the line back then before the 18S was available. 

[gr8ps]

12 hours ago, mrelwood said:

Which is why I never experienced the abrupt KingSong tilt-back that many people talk about.

I never understood why people hate Kingsong's tilt-back as much as they do. Sure, it's abrupt but it's not too difficult to get used to, especially if you expect it. The tilt-back is usually preceded by the beeping noise so it almost never comes as a surprise. I'm getting my first real Gotway so I'm a bit apprehensive on how that tilt-back will work. It blows my mind that you are able to disable it completely as well on a Gotway. 

[Lutalo]

9 hours ago, Smoother said:

Sorry to hear you got injured, and sorry you have lost your confidence. If you upgrade don't upgade to the 16s, it's too slow for you.  You sound like you like some speed so go up to a 45+kph wheel AND DONT RIDE THE TILT BACK.

As for trusting your wheel; any wheel is a lot more trustworthy if you don't ride it at max speed, (see my personal 90% of max speed rule) stuff like this really does keep you out of hospital.

Right. Couple of awesome 16" wheels from which to select: Gotway Nikola offers excellent performance if somewhat lacking ergonomically; it looks huge, wide, and a bit of a hassle if you have to lift it. how much that matters depends on how much you commute. Although I am sure I would love the performance, as a primarily urban rider/commuter I can't see the 84 volt Nikola at the top of my personal wheel list. I can wait for the 16X. 

I expect it to be better than the Nikola as a main wheel for DC striver duty; perhaps an even better all arounder. We will soon see.

I don't usually get overly excited about 16" wheels, but they are starting to appeal to me, and the top of that list so far  the upcoming 100 volt version of the Nikola. This wheel represents an entirely different matter altogether when it comes to wheels. For me, it would be a purely recreational wheel, and I would be absolutely certain to recreate it quite heavily and quite often 😂😂: close to Monster level speed married to Kingsong level features and comfort, and totally lacking in MSX butt-ugliness? Promise of great range? Awww man! Then I remember the price point.  

Edited June 8, 2019 by Lutalo

[mrelwood]

6 hours ago, gr8ps said:

I'm getting my first real Gotway so I'm a bit apprehensive on how that tilt-back will work.

I find the MSX tilt-back great for myself. It is so slow and unintrusive, I never even realize when it is on. I just feel that going faster would require pushing it more than I’m willing to do at those speeds, so I simply don’t go any faster.

6 hours ago, gr8ps said:

It blows my mind that you are able to disable it completely as well on a Gotway.

Mine too. And since the theory still exists that the tilt-back itself could cause an actual cut-out, many people indeed disable it alltogether. I’m pretty sure it can’t happen on these modern fast wheels, if not just because there is so much reserve left at the maximum available tilt-back at 48km/h.

[Smoother]

6 hours ago, mrelwood said:

I find the MSX tilt-back great for myself. It is so slow and unintrusive, I never even realize when it is on. I just feel that going faster would require pushing it more than I’m willing to do at those speeds, so I simply don’t go any faster.

Mine too. And since the theory still exists that the tilt-back itself could cause an actual cut-out, many people indeed disable it alltogether. I’m pretty sure it can’t happen on these modern fast wheels, if not just because there is so much reserve left at the maximum available tilt-back at 48km/h.

I wonder what a King Song would be like if one could disable tilt back.  There's a huge speed reserve in there, but something like a vibrating pebble watch would be essential to keep away from the dreaded "cut out"

[Smoother]

14 hours ago, gr8ps said:

I never understood why people hate Kingsong's tilt-back as much as they do. Sure, it's abrupt but it's not too difficult to get used to, especially if you expect it. The tilt-back is usually preceded by the beeping noise so it almost never comes as a surprise. I'm getting my first real Gotway so I'm a bit apprehensive on how that tilt-back will work. It blows my mind that you are able to disable it completely as well on a Gotway. 

if you don't fear King Song tilt back then you haven't experienced a violent tilt back.  I envy you.  Here's my suggestion, accelerate hard to max speed.  When the wheel suddenly shoots violently ahead of you and dips violently backwards so that the pedals drop out from under your heels while you are trying to stay upright at high speed, report back and let us know how it made you feel, (or what injuries you sustained).  It's not the tilt back that is feared, it's the "violent" tilt back.  not all tilt back is violent.  But when it is. it is usually at speed and, in my opinion, it is exactly like when you lift the wheel off the ground and tilt it.   Once the wheel passes a set speed it goes into this max speed routine, there is nothing you can do to slow it down, in other words, tilting it back the other way will not slow it down.  It stays at max speed for a fixed amount of time, then it shuts down.  If you are riding it when this happens, it's all over but for the crying.  If you think this is impossible, remember that when you lift the wheel and tilt it to max speed, the wheel has no idea that you have lifted it off the ground; as far as it's concerned, there is a rider on board. It just keeps accelerating until the tilt back threshold is reached, that's when it violently accelerates to max, stays for a few seconds then resets to dead.

Edited June 8, 2019 by Smoother

[mrelwood]

39 minutes ago, Smoother said:

Here's my suggestion, accelerate hard to max speed. 

This is exactly why I haven’t, and I suppose never will experience the violent tilt-back: I’m not nearly crazy enough to accelerate fast above 30km/h on any wheel. My counter-suggestion to all riders: Never ever accelerate fast anywhere near the max speed! Even if the tilt-back is turned off.

It was proposed some time ago that the firmware should start the tilt-back a lot earlier if the rider is accelerating fast. I think all firmwares should definitely be changed to do exactly that.

I haven’t seen any discussion on the event horizon for the neverending tilt-back. Do we know any numbers, how much above the tilt-back speed does it happen? Free air tilt-back is not the best example, since the wheel sees zero effect to pedal position from the tilt-back acceleration. That’s why it accelerates at an increasing rate. In your example the wheel eventually gets in front of the rider, so the wheel will be tilted backwards before it reaches the rotational max speed of the tire. In free air that doesn’t happen.

Edited June 8, 2019 by mrelwood

[Smoother]

23 minutes ago, mrelwood said:

This is exactly why I haven’t, and I suppose never will experience the violent tilt-back: I’m not nearly crazy enough to accelerate fast above 30km/h on any wheel. My counter-suggestion to all riders: Never ever accelerate fast anywhere near the max speed! Even if the tilt-back is turned off.

It was proposed some time ago that the firmware should start the tilt-back a lot earlier if the rider is accelerating fast. I think all firmwares should definitely be changed to do exactly that.

I haven’t seen any discussion on the event horizon for the neverending tilt-back. Do we know any numbers, how much above the tilt-back speed does it happen? Free air tilt-back is not the best example, since the wheel sees zero effect to pedal position from the tilt-back acceleration. That’s why it accelerates at an increasing rate. In your example the wheel eventually gets in front of the rider, so the wheel will be tilted backwards before it reaches the rotational max speed of the tire. In free air that doesn’t happen.

Accelerating hard to max speed is something I actually haven't done (accelerating hard to max available battery is more my speed), It was just the simplest way to describe getting into a VTB (violent tilt back)  I've had mine various ways but almost all because my first wheel had a tiny battery (340Wh) and lowish top speed 30kph.  Marty had the same wheel with double the battery and I believe it makes all the difference.

And it was me who proposed acceleration related tilt back phase-in, like anyone important is listening 

As for the never ending tilt back, you make a good point. I just went to test fee air tilt back (to avoid making another un-fact checked statement) and one can indeed reverse the effect by forcibly tilting the wheel backwards, but the transition is VERY abrupt and there seems to be no progression in it.  One moment it's full speed ahead, then after tilting it back a long way it slams into what seems like a forward crawl.  There is a distinct thump; almost like the program won't respond until a specific dergee of tilt is reached, then BAM!. (Much like your testing a few weeks ago of the 45 deg forward, backward cut out). I would not like to experience this while standing on the wheel, either. So I stand corrected: never ending tilt back doesn't exist (for King Song) but what is there in it's place is not much more appealing.  Usually when riding, I have fallen off by then so I have not experienced it; as far as I am aware. As any face planter knows, in a wheel initiated ( as opposed to a rock or kerb, etc) things happen so quickly, it's hard to diagnose the event afterwards.

[gr8ps]

12 hours ago, Smoother said:

if you don't fear King Song tilt back then you haven't experienced a violent tilt back.  I envy you.  Here's my suggestion, accelerate hard to max speed.  When the wheel suddenly shoots violently ahead of you and dips violently backwards so that the pedals drop out from under your heels while you are trying to stay upright at high speed, report back and let us know how it made you feel, (or what injuries you sustained).  It's not the tilt back that is feared, it's the "violent" tilt back.  not all tilt back is violent. 

I've experienced the violent tilt back many times. For me, the tilt forward when I aggressively lean in is a lot scarier than the tilt-back - I have a split second where I fear that the wheel won't be able to keep me upright and the tilt-back almost comes as a relief that it didn't. When it tilts back, the wheel doesn't really shoot ahead of me, I just rotate my ankle backwards.

Edited June 8, 2019 by gr8ps

[mrelwood]

13 hours ago, gr8ps said:

I've experienced the violent tilt back many times. For me, the tilt forward when I aggressively lean in is a lot scarier than the tilt-back - I have a split second where I fear that the wheel won't be able to keep me upright and the tilt-back almost comes as a relief that it didn't. When it tilts back, the wheel doesn't really shoot ahead of me, I just rotate my ankle backwards.

I hereby announce that for the ongoing contest of Russian Face-Plant Roulette, mr. @gr8ps is taking a strong lead as the #1 winner candidate! The eventual contest winner will be announced at a later time, and I’m pretty sure we all know what the winning prize is!

Don’t hesitate still to participate though, several awards await!

[eddiemoy]

On 8/30/2018 at 8:23 PM, maxkan said:

We need some redundancy then, to reduce a probability of failure.

You're a KS representative, right? Let them know we need a device that is not only fun but safe as well.

And its good for the business. Each of those accidents reduce KS sales

Probability of batter failure go down the more parallel pack you have.  The 16S has 4, same as the 18L, but the XL has two extra, or 6.  Redundancy is difficult to build into a unicycle.  I think IPS tried to build one,the S5, was twice as heavy as the i5.  Think they went out of business. 

[Chriull]

15 hours ago, gr8ps said:

I've experienced the violent tilt back many times. For me, the tilt forward when I aggressively lean in is a lot scarier than the tilt-back

That's good that this is cary - one is just a little step away from scratching with the face on the asphalt ....

15 hours ago, gr8ps said:

- I have a split second where I fear that the wheel won't be able to keep me upright and the tilt-back almost comes as a relief that it didn't.

Such situations just happened to me when i underestimated small bumps/irregularities while accelerating - the wheel stays behind, the face goes down and one hears in the brain "gotcha - you're gonna make your first faceplant noe". And suddenly the wheel is still making it to catch up and everythings fine but the blood pressure 

If this really happens on a regular basis while riding (the tilt forward) please get a more powerful wheel and dress up with safety gear. 

15 hours ago, gr8ps said:

When it tilts back, the wheel doesn't really shoot ahead of me, I just rotate my ankle backwards.

That sounds like a great handling of the tiltback! ... If one shifts the weight backwards too to stop the acceleration.

[Mono]

3 minutes ago, Chriull said:

If this really happens on a regular basis while riding (the tilt forward) please get a more powerful wheel and dress up with safety gear. 

How about just going by 2km/h slower on a regular basis?

[Chriull]

58 minutes ago, Mono said:

How about just going by 2km/h slower on a regular basis?

Imho the "prob" here is acceleration and not so much speed...

[gr8ps]

2 hours ago, Chriull said:

Imho the "prob" here is acceleration and not so much speed...

Yep - I don't gun it when I'm going top speed. It happens to me at low speeds when I lean forward to accelerate to catch up to someone, also, the acceleration part is pretty fun. I always have a full face helmet on and wrist guards at a minimum. I think I'm a safe/conservative rider, typically. I just need a little more than what the 16S can give now. 

[Mono]

2 hours ago, Chriull said:

Imho the "prob" here is acceleration and not so much speed...

Then, more practice should do. Low speed pedal dips become spectacularly unscary after a while. After all, when the pedal fully gives in, speed is the decisive scare and hurt factor.

My more profound point though was my persistent amazement that safety suggestions seem to reflexively go to a change of equipment instead of change of behavior. I know that equipment is easier to change. But getting a stronger wheel is almost like asking for getting into the very same troubling situation just at a 5-10km/h higher speed.