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My first High Speed crash ever and it was on the S22


Rawnei

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1 hour ago, MetricUSA said:

Ah.... I think it just shows you to STOP MAX SPEED RIDING like an idiot... How many time it has to be said on an unicycle...'DON'T GO TO MAX SPEED LIMIT'??? 

Aren't you a bundle of sunshine.

Mechanisms that clearly signals and prevents us from going over the PWM limit that actually works like for example the Begode Custom Firmware works really really well, you can cruise at the set PWM knowing that you are very safe below the max power limit, if all wheels had this we would all be much safer.

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On 12/30/2022 at 5:00 AM, Rawnei said:
  • ...but also none of my safety mechanisms alerted me of what was about to happen, it's possible that wheel was beeping but I can't hear wheel beeps over the wind wearing a helmet which I think is the usual situation for most riders, I could feel no tilt-back from the wheel, none of my EUC World alarms that I have configured was triggered (I checked the logs and will detail more on this below), I usually rely on EUC World and respect those alarms.

I've personally noticed a ~0.5s delay between wheel alarms and EUC World alarms and quite a lot can happen in half a second. I contacted them about it but never heard back as to why that's the case or how to reduce it. Consequently, I ride a bit more conservatively when near the top end even with the alarms and when I do hear an alarm, knowing it's already delayed I immediately get off the gas. I'm not sure if Darknessbot has the same issue or if it's an android issue or what.

 

Edited by level9
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19 hours ago, level9 said:

I've personally noticed a ~0.5s delay between wheel alarms and EUC World alarms and quite a lot can happen in half a second.

The wheel measures values roughly about 100 times a second. But it sends a(n averaged) value over bluetooth only 3-5 times a second.

So one has already up to some 0.2-0.33s delay. If one has bad luck some peak value can "get softened"/"vanish" due to averaging (however this is implemented in the firmware).

Bluetooth stack needs some time, too. Once there is bad transmission quality further delays can arise by retransmission/dropped packages. 

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6 hours ago, Chriull said:

The wheel measures values roughly about 100 times a second. But it sends a(n averaged) value over bluetooth only 3-5 times a second.

So one has already up to some 0.2-0.33s delay. If one has bad luck some peak value can "get softened"/"vanish" due to averaging (however this is implemented in the firmware).

Bluetooth stack needs some time, too. Once there is bad transmission quality further delays can arise by retransmission/dropped packages. 

Yeah that's much too long. Then add in the typical reaction time to various stimuli..

The average reaction time for humans is 0.25 seconds to a visual stimulus, 0.17 for an audio stimulus, and 0.15 seconds for a touch stimulus.

It would seem there is much room for safety related improvements here. Perhaps manufacturers should add a vibration alarm to the wheel itself which would result in the fastest stimulus response plus elimination of the bluetooth latency. I'd like to see something like this.

 

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6 minutes ago, level9 said:

Yeah that's much too long. Then add in the typical reaction time to various stimuli..

The average reaction time for humans is 0.25 seconds to a visual stimulus, 0.17 for an audio stimulus, and 0.15 seconds for a touch stimulus.

It would seem there is much room for safety related improvements here. Perhaps manufacturers should add a vibration alarm to the wheel itself which would result in the fastest stimulus response plus elimination of the bluetooth latency. I'd like to see something like this.

 

It already exists, tiltback, but it needs to be improved on the S22 and most other wheels, if implemented correctly it's a very good safety feature.

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15 minutes ago, Rawnei said:

It already exists, tiltback, but it needs to be improved on the S22 and most other wheels, if implemented correctly it's a very good safety feature.

Unfortunately tiltback requires significantly more power which is the problem when you're already out of power. It's kind of dumb when you think about. Let's alert the user the wheel is out of power by drawing even more power! :huh: In contrast, the power requirements for vibration would be minimal.

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7 minutes ago, level9 said:

Unfortunately tiltback requires significantly more power which is the problem when you're already out of power. It's kind of dumb when you think about. Let's alert the user the wheel is out of power by drawing even more power! :huh: In contrast, the power requirements for vibration would be minimal.

PWM based tiltback happens at a certain set PWM before you run out of power, if you tried a well implemented one you would understand just how good it is, S22 is speed based which sucks plus the it's very weak and easily not felt/overpowered.

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How hard is to limit yourself? If wheel can go 70 why go 70? :D Go 60-65 and be happy. No tiltback, alarms, nothing. And more importantly - no crashing.

Yeah i get you can ride 70/70.. And wheel has its own safety already built-in. But each time you go max speed, you are risking to get a cutout.. 

 

I will never ride 100% speed on self balancing wheel. It's just asking for a trouble! Small dip/bump in road and your ass also will go bump on the ground. :rolleyes: (Doh if safety is well built - it should not..) But still i would ride 90% speed even on safest EUC.

Edited by Funky
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10 minutes ago, Rawnei said:

PWM based tiltback happens at a certain set PWM before you run out of power, if you tried a well implemented one you would understand just how good it is, S22 is speed based which sucks plus the it's very weak and easily not felt/overpowered.

I have speed based alarms disabled (which are useless IMO since rider weight, terrain, wind speed and battery level varies). I only use 'safety margin' which is KS's load based implementation. Not that that really matters much anyway in a sudden overlean - there is still insufficient power to generate tiltback. In order to have sufficient power in that case they would have to add presumably a fair amount of capacitors to the board and also the motor would still need to be able to handle the power spike.

I won't disagree that the S22 tiltback implementation may be poor compared to other wheels but I wouldn't rely on tiltback on any wheel. I've seen way too many people crash without warning when riding at the limits and the manufacturer didn't matter.

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28 minutes ago, Funky said:

How hard is to limit yourself? If wheel can go 70 why go 70? :D Go 60-65 and be happy. No tiltback, alarms, nothing. And more importantly - no crashing.

Yeah i get you can ride 70/70.. And wheel has its own safety already built-in. But each time you go max speed, you are risking to get a cutout.. 

 

I will never ride 100% speed on self balancing wheel. It's just asking for a trouble! Small dip/bump in road and your ass also will go bump on the ground. :rolleyes: (Doh if safety is well built - it should not..) But still i would ride 90% speed even on safest EUC.

That's what tiltbacks and alerts are for, to tell you what speed/power output you are at... if you think you always know what speed you are riding at or if you are constantly watching a display to find out you are already taking risks.

4 minutes ago, level9 said:

I have speed based alarms disabled (which are useless IMO since rider weight, terrain, wind speed and battery level varies). I only use 'safety margin' which is KS's load based implementation. Not that that really matters much anyway in a sudden overlean - there is still insufficient power to generate tiltback. In order to have sufficient power in that case they would have to add presumably a fair amount of capacitors to the board and also the motor would still need to be able to handle the power spike.

I won't disagree that the S22 tiltback implementation may be poor compared to other wheels but I wouldn't rely on tiltback on any wheel. I've seen way too many people crash without warning when riding at the limits and the manufacturer didn't matter.

If you get the chance please try the custom firmware for Begode wheels, it's very well implemented with plenty of margin.

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1 hour ago, level9 said:

Unfortunately tiltback requires significantly more power which is the problem when you're already out of power. It's kind of dumb when you think about.

It’s actually smart enough to outsmart a lot of people…. :P

Yes, tilt-back uses power, just like it takes power for you to start braking.

 The only way for the rider to lean back and brake is to first press on one’s toes first, so that the wheel will accelerate in front of the rider.

 Sound familiar? Yup, that’s exactly the same thing a tilt-back does.

Since the tilt-back can come as a surprise, it is possible that the rider would continue pushing against it for a short while, during which it might use slightly more power than if the rider were to do it themself. I really don’t think it’s a difference that makes any practical difference though.

 So if you ride in a way that doesn’t have the power left for a tilt-back, you probably wouldn’t have the power left to start braking yourself either.

 

1 hour ago, level9 said:

In contrast, the power requirements for vibration would be minimal.

Don’t know about you, but I wear thick soled high top boots with well cushioning insoles, and thick motorcycle pants. And the tire and the whole wheel vibrates near top speed quote a bit anyway. I don’t think a vibrator large enough to matter would fit in our wheels without a notable redesign.

 

43 minutes ago, Funky said:

I will never ride 100% speed on self balancing wheel.

43 minutes ago, Funky said:

But still i would ride 90% speed even on safest EUC.

I hear you, and I believe that’s a safe approach.

 But 90% of what exactly? There’s the no-load speed at full battery, no-load at empty battery, no-load at current battery level, a maximum theoretical unlimited riding speed also at several battery reference points, an advertised max riding speed (can also vary between distributors), and one or even two maximum limited speeds on some wheels, which also go down with battery level.

If you want a constant safety headroom, be sure to use a fixed constant as a reference as well, and not different ones for different manufacturers.

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15 minutes ago, mrelwood said:

Yes, tilt-back uses power, just like it takes power for you to start braking.

 The only way for the rider to lean back and brake is to first press on one’s toes first, so that the wheel will accelerate in front of the rider.

Your braking method must be different than mine. I sit down. The pressure is immediately on my heels, not my toes and it's the fastest way to shift the center of gravity to the rear.

17 minutes ago, mrelwood said:

 So if you ride in a way that doesn’t have the power left for a tilt-back, you probably wouldn’t have the power left to start braking yourself either.

 

Not in my experience. I've overleaned my S18 trying to cross an intersection quickly. This was an aggressive but not sudden overlean. From a standstill, I accelerated and held the same lean position while crossing. The wheel eventually ran out of torque and the pedals dipped forward to dump me. I immediately dropped my butt and she re-engaged. Admittedly, I was surprised how fast she recovered once the overlean condition was cleared. Kudos to KS on this one - very responsive firmware.

24 minutes ago, mrelwood said:

Don’t know about you, but I wear thick soled high top boots with well cushioning insoles, and thick motorcycle pants. And the tire and the whole wheel vibrates near top speed quote a bit anyway. I don’t think a vibrator large enough to matter would fit in our wheels without a notable redesign.

 

Perhaps. I still think it's worth looking into.

The current mechanism wherein when running out of a resource, to then consume even more of said resource which is in shortage is, by definition, a bad design. Nobody designs systems this way. At least no engineer that wants to keep their job ;).

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1 hour ago, Rawnei said:

That's what tiltbacks and alerts are for, to tell you what speed/power output you are at... if you think you always know what speed you are riding at or if you are constantly watching a display to find out you are already taking risks.

I ride most of my time around 35km/h out of max 50km/h of my wheel. My alarms are set at 38 and 42. And i rarely hear the second one.. (Tiltback at 50 because i don't need it.)

I'm pretty good at telling speed, because if i try to go little faster, first alarm instantly kicks in. I sometimes keep riding the first alarm as they are very quiet beeps. Some time i also ride the 42km/h alarm. But very, very rarely and only on smooth straight road.

Yeah those speed are "slow" for some. But on sidewalks it's plenty. Ofc i slow down even more around people.. (I have done some tests myself. Read lower..)

1 hour ago, mrelwood said:

I hear you, and I believe that’s a safe approach.

 But 90% of what exactly? There’s the no-load speed at full battery, no-load at empty battery, no-load at current battery level, a maximum theoretical unlimited riding speed also at several battery reference points, an advertised max riding speed (can also vary between distributors), and one or even two maximum limited speeds on some wheels, which also go down with battery level.

If you want a constant safety headroom, be sure to use a fixed constant as a reference as well, and not different ones for different manufacturers.

90% of max EUC speed. :D (The riding speed. Not the free spin speed.)

Lowest my safety margin ever has been, was when i did 45km/h speed run at 50% battery. It dropped down to 13%.

I have even noticed only times my safety margin drops under 25%, is when i ride "faster" than my usual riding speeds. When i go over 42km/h. (Battery being at 100% or 50% made almost zero difference in my riding style.) I don't accelerate fast and don't do quick movements when i go over 42km/h. 

And because i charge my wheel at ~45% battery.. I don't need to worry about "too empty" problems. 

I even have tried going 0-40 fast as possible. Even then my safety margin was over 20% all times. Like i mentioned - only times it goes under 20% is when i ride over 42km/h.

 

That's why my thumb of a rule is riding 90% out of 100%. If wheel can go 50. You don't have to ride 50.. Ride max 45.

In my case i ride around 35-40. It's my sweet spot. :D And plenty of safety margin left. No matter of battery levels. (When i did range test, wheel started to speed limit me around ~30%.) Oh and in EUCW i have safety margin put at 20%. I have heard it only ~4 times over a year. -Not including the tests.

Edited by Funky
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5 hours ago, level9 said:

The current mechanism wherein when running out of a resource, to then consume even more of said resource which is in shortage is, by definition, a bad design. Nobody designs systems this way. At least no engineer that wants to keep their job ;).

tell that to smoke alarms and countless other little devices. when their battery is low, they either start beeping or doing light shit. 

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53 minutes ago, dredwheel said:

tell that to smoke alarms and countless other little devices. when their battery is low, they either start beeping or doing light shit. 

ahh but there is a difference here. You are referring to a steady-state power draw in a controlled environment. The devices are not responding by asking for more power than what is available - they're simply reducing runtime with the alarms. Big difference.

EUCs are neither steady-state power draws nor operating in a controlled environment. The inputs are variable. The issue at hand is what happens when a rider asks for more power than what is available and the amount of power the rider may request in excess is also variable. The tiltback mechanism operates under the assumption that it can meet the users excess power requirements and add even more power draw on top! Naturally, such a design would be prone to failure.

Think about this as the difference between available capacity (watt/hours) vs. voltage. Tiltback needs more voltage when voltage demand is already in excess.

In order to get an EUC to behave like a smoke alarm if you will, they would have to add capacity for power spikes. Lots of capacitors as I've mentioned.. and even then, could probably only generate 1-2 seconds of tiltback (depending on the level of excess of the riders input/overlean).

 

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8 hours ago, level9 said:

Not in my experience. I've overleaned my S18 trying to cross an intersection quickly. This was an aggressive but not sudden overlean. From a standstill, I accelerated and held the same lean position while crossing. The wheel eventually ran out of torque and the pedals dipped forward to dump me. I immediately dropped my butt and she re-engaged. Admittedly, I was surprised how fast she recovered once the overlean condition was cleared. Kudos to KS on this one - very responsive firmware.

That's because of S18, it doesn't have a very powerful battery setup and it's easy to overlean like that, it's actually known phenomena many people complained about it on the S18, also overall KS tiltback implementation is pretty crude and happens way too late with too little margin.

8 hours ago, Funky said:

I ride most of my time around 35km/h out of max 50km/h of my wheel. My alarms are set at 38 and 42. And i rarely hear the second one.. (Tiltback at 50 because i don't need it.)

I'm pretty good at telling speed, because if i try to go little faster, first alarm instantly kicks in. I sometimes keep riding the first alarm as they are very quiet beeps. Some time i also ride the 42km/h alarm. But very, very rarely and only on smooth straight road.

Well there you go, you're talking about riding at certain speeds but you need a mechanism for this that tells you about it and that's exactly what you are using, an alarm or/ tiltback, since at higher speeds it's difficult to hear the beeper over wind-noise while wearing a helmet you need something else, application alarm or tiltback.

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On 1/23/2023 at 12:18 AM, level9 said:

Your braking method must be different than mine. I sit down. The pressure is immediately on my heels, not my toes and it's the fastest way to shift the center of gravity to the rear.

It’s not about a specific braking method. You just can’t shift your CoG back without taking support from somewhere, in this case pushing against the pedals with your toes.

 Just like if you are standing across a ledge with the front half of your feet past the edge, in the air. You can’t really shift your weight back because you would need to push against a solid object with your toes to move your CoG.

 It’s relatively easy to prove: Roll a mattress behind an analogue weight scale, so that you can stand with your feet level while only the front half of your feet are on the scale. Assume a riding position, a small forward lean. Now watch the scale as you shift your weight back into a braking position. The value on the scale gets bigger at first.

 

On 1/23/2023 at 6:06 AM, level9 said:

The issue at hand is what happens when a rider asks for more power than what is available

A rider of a self-balancing vehicle simply must understand that they are not tapping into an endless source of limitless power. If they don’t, no safety mechanism on earth can be completely fool proof.

 The tilt-back isn’t intended to engage when the wheel is out of power. It’s intended to do so before that. Just like the fire alarm warns about the battery before it runs out. No tilt-back is perfect though, and there can be situations where with enough intent (or foolishness) you could push the wheel over the limit without the tilt-back even engaging.

@Freestyler’s PWM tilt-back firmware for Begode wheels is probably the best tilt-back implementation there is. I know the V11 monitors for the wattage consumption among other things, but it still isn’t as good as a simple PWM tilt-back.

 

On 1/23/2023 at 6:06 AM, level9 said:

Tiltback needs more voltage when voltage demand is already in excess.

Current, not voltage. And if the current usage is already in excess, the tilt-back implementation has already failed. Either it should’ve started sooner, or the rider needs to get a grasp on reality and reconsider one’s riding behavior.

 

On 1/23/2023 at 12:27 AM, Funky said:

90% of max EUC speed. :D (The riding speed. Not the free spin speed.)

The max riding speed already has a big difference in the available safety headroom between wheels, so your 90% isn’t a fixed amount of headroom. The 16X for example doesn’t have sufficient headroom left at it’s max speed, and many riders stay below 43km/h because of that. 90% of the max riding speed is barely safe for generic use, let alone heavier riders.

I wouldn’t have the guts to ride the 16X at 90%, but I have no problem reaching 100% even on the Fancy mode on my V11 (55km/h).

 Also, I know you don’t care much about Begode wheels, but what would be the maximum “riding speed” of a Master? Or a Sherman?

On 1/23/2023 at 12:27 AM, Funky said:

I have even noticed only times my safety margin drops under 25%,

The PWM safety margin is a great measure though! Keep the remaining margin above 20% and you are practically safe, at any speed.

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2 hours ago, mrelwood said:

The max riding speed already has a big difference in the available safety headroom between wheels, so your 90% isn’t a fixed amount of headroom. The 16X for example doesn’t have sufficient headroom left at it’s max speed, and many riders stay below 43km/h because of that. 90% of the max riding speed is barely safe for generic use, let alone heavier riders.

16X - 90% = 44km/h (Doh most people know it's real max speed is~48km/h) Making it 43km/h as you said.. Same time if i had 16x, i would never go past 40km/h on it myself.

2 hours ago, mrelwood said:

 Also, I know you don’t care much about Begode wheels, but what would be the maximum “riding speed” of a Master? Or a Sherman?

As i don't really ride faster than ~40-44km/h. If i bought one of those "big" wheels. I would make that -15% of max riding speed.. So i would try to ride below 85% of its max speed. Doh knowing how i ride, etc.. I would never go faster than 60km/h. So my guess it's well under max speed.

Bigger the wheel, the faster you go, the more "extra" safety margin is good to have. (Not needed.. But good to have.)

2 hours ago, mrelwood said:

The PWM safety margin is a great measure though! Keep the remaining margin above 20% and you are practically safe, at any speed.

Yeah i never really hear that alarm, because i never really ride that fast. And don't do quick accelerations, etc..

Edited by Funky
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6 minutes ago, Funky said:

As i don't really ride faster than ~40-44km/h. If i bought one of those "big" wheels. I would make that -15% of max riding speed.. So i would try to ride below 85% of its max speed. Doh knowing how i ride, etc.. I would never go faster than 60km/h. So my guess it's well under max speed.

Speed is relative to battery charge and power demand.

Begode Custom FW PWM tiltback would trigger at 80% PWM leaving you with a 20% margin when headlight will flash, wheel will transmit actual wheel alarm to you app and tiltback will gradually start to tell you that you've reached the limit, it's very nice, on the Master you could customize it further if you want it to trigger even earlier.

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1 hour ago, Rawnei said:

Speed is relative to battery charge and power demand.

Begode Custom FW PWM tiltback would trigger at 80% PWM leaving you with a 20% margin when headlight will flash, wheel will transmit actual wheel alarm to you app and tiltback will gradually start to tell you that you've reached the limit, it's very nice, on the Master you could customize it further if you want it to trigger even earlier.

But as i mentioned i never have had my wheel lower than 50%. I could imagine that most wheels can do max speed at 50% still? Or are they getting already limited at 50% battery? Also not being a crazy driver, i could imagine my power demand would be quite low. I'm 280lbs going 20km/h or 40km/h and my 18xl doesn't even scream at me.

Hopping on bigger wheels - i would have way, way more headroom.. Do do crazy/daring things. :D 

Yeah i have seen the custom PWM on begoddy wheels. - One of best implanted tiltbacks, i think. As pedals are lifting very slowly. And more you get to 0% the harder it's tilting. (If i got it right.) Just have seen some videos, etc.. As i will never have Begode wheel, (Mostly because quality isn't there..) haven't really looked into it. And personally don't need the tiltback. (I can hear EUCW the most quiet beeps every time.) Sound alarms are just okay for my. But if i were to drive faster, where you can't hear the beeps anymore. Great tiltback would be needed for sure.

Edited by Funky
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