What makes Kingsong,s safe?

[Simon Lovell]

 Does anyone know what Kingsong have actually done to make their wheel,s safer than other wheels?

Is it true that it will never cut out on you? OR is it still possible to make the wheel cut out, but just harder to do? 

Having learnt to ride defensively on a cheap generic wheel it would be good to know how far the safe limits might extend on my new KS16.

[OliverH]

It's always good to have respect for technology, failures and different behaviours because of riders weight. 

[SlowMo]

There is no safe wheel. Always be aware and never be too confident. Even Kingsong units fail.

[DS]

Standard measures - sound warnings and tilt back. More power and big capacity battery mean harder to overlean but in direct relation with the rider's weight.

The introduced fan will help the mosfets not to overheat.

The rest - I hope the overall electronics and mechanical parts are with high quality, thoughtfully assembled and meticulously quality control checked.

And always have on mind - even NASA fails from time to time...

[Keith]

11 hours ago, Simon Lovell said:

 Does anyone know what Kingsong have actually done to make their wheel,s safer than other wheels?

Is it true that it will never cut out on you? OR is it still possible to make the wheel cut out, but just harder to do? 

Having learnt to ride defensively on a cheap generic wheel it would be good to know how far the safe limits might extend on my new KS16.

As both @SlowMo and @OliverH have said, all wheels can fail, none of them have any redundancy built in so a mechanical or electrical failure can always occur. 

However, poor design can make the risks way way higher and there are a number of scenarios that a designer should see as normal operation thus should NEVER result in a faceplant. KingSong have captured more of those than many other manufacturers. The worst manufacturers appear to use a BMS (Battery Management System) intended for electric bikes which is downright dangerous on a balancing device. For example:

Low battery: many wheels BMS will cut power to protect the battery, a good wheel should beep and tilt back to prevent you riding further.

Excessive current: again poor design BMS will kill power (and possibly you!) a good wheel will beep and tilt back to slow you down. 

Excessive speed: torque keeps you balanced; as speed increases available torque gets lower until at absolute max speed there is zero left and you faceplant.  It might not be obvious, but to tilt you back requires more torque and for the wheel to accelerate harder. A good wheel has to beep and start tilting you back well before you reach its absolute max speed and make it as difficult as possible for you to try to ride even faster. Remember as battery runs down so does voltage and, therefore, max power and max speed. Not taking that into account can make a safe full battery wheel dangerous at low battery.

Overheating: prolonged high power - heavy rider going up long hill for example - can get things hot enough to fail. A good wheel will, again, beep and tilt back if getting too hot (a better wheel will dissipate the heat effectively as well!)

Prolonged downhill: regenerative braking has to 'dump' the power somewhere in order to resist the weight of the rider (torque) and dissipate the energy of going down the hill/ stopping. Quite high voltages can be generated. The wheel needs to handle these. This is the trickiest one, as I found to my cost, even the KS-14C does not seem to handle this if it's battery is full as there is nowhere for the power to go. In all other situations it tilts back to force you to descend slower and reduce the power generated.

As you can also see, in the above list, much bigger batteries, with correspondingly lower internal resistance will also go an awful long way to make all of the above situations except overheating less likely to occur.

[OliverH]

2 hours ago, Keith said:

As both @SlowMo and @OliverH have said, all wheels can fail, none of them have any redundancy built in so a mechanical or electrical failure can always occur. 

However, poor design can make the risks way, way higher and there are a number of scenarios that a designer should see as normal operation thus should NEVER result in a faceplant. KingSong have captured more of those than many other manufacturers. The worst manufacturers appear to use a BMS intended for electric bikes which is downright dangerous on a balancing device. For example:

Low battery: many wheels BMS will cut power to protect the battery, a good wheel should beep and tilt back to prevent you riding further.

Excessive current: again poor design BMS will kill power (and possibly you!) a good wheel will beep and tilt back to slow you down. 

Excessive speed: torque keeps you balanced as speed increases, available torque gets lower until at absolute max speed there is zero left and you faceplant.  It might not be obvious, but to tilt you back requires more torque and for the wheel to accelerate harder. A good wheel has to beep and start tilting you back well before you reach its absolute max speed and make it as difficult as possible for you to try to ride even faster. Remember as battery runs down so does voltage and, therefore, max power and max speed. Not taking that into account can make a safe full battery wheel dangerous at low battery.

Overheating: prolonged high power, heavy rider going up long hill for example, can get things hot enough to fail. A good wheel will, again, beep and tilt back if getting too hot (a better wheel will dissipate the heat effectively as well!)

Prolonged downhill: regenerative braking has to 'dump' the power somewhere in order to resist the weight of the rider (torque) and dissipate the energy of going down the hill/ stopping. Quite high voltages can be generated. The wheel needs to handle these. This is the trickiest one, as I found to my cost, even the KS-14C does not seem to handle this if it's battery is full as there is nowhere for the power to go. In all other situations it tilts back to force you to descend slower and reduce the power generated.

As you can also see, in the above list, much bigger batteries, with correspondingly lower internal resistance will also go an awful long way to make all of the above situations except overheating less likely to occur.

In my opinion there's no real design, testing or a safety concept an EU is built on. There's only a difference in more or less safe.

[Cloud]

19 hours ago, OliverH said:

In my opinion there's no real design, testing or a safety concept an EU is built on. There's only a difference in more or less safe.

This is true. Eucs are inherently not fool proof. What matters is which are more safe than others, knowing how to utilize these safeties in one's riding and to some people - which will be considered " officially safe" Per the consumer product safety commission (cpsc) all eucs that are not UL2272 certified are automatically considered defective and unsafe. This is a new standard for euc battery/ charger safety that came out. It intends to guarantee that euc battery can withstand certain extreme conditions. This is the official position. However the standard doesnt cover the overall euc safety - only how the battery/ charger works with the overall design. There are other factors inherently containing some risks by virtue of how the wheel rides.

however for an end user it doesnt hurt to have the peace of mind knowing there are certain safeties built into certain wheel models. What makes a wheel safe is really knowing how a particular model works, where its limits are so the rider's behavior can be adjusted accordingly. However, relying too much on safeties built into the wheel can lead to exposure to greater risks. A perfect combination to avoid an unsafe situations is compliance  with the 3 conditions below 1) having a wheel with useful safety mechanisms relevant to a particular rider's style 2) understanding of these safety mechanisms and knowing how to utilize them by the rider, 3) riding far below the risk zone so as not to base one's riding style on relying solely on these safeties in the risk zone.

[OliverH]

The overall safety will be defined in the European ISO 12100 Typ C standard. I can't go in detail right now but it will improve the electric unicycles. 

[edwin_rm]

From personal experience riding one, this is what makes King Song safe: they don't lie about their top speed. They don't list the cutoff speed as the max speed. They don't have an app that innacurately displays 5 kph over the real speed.

Also, KS has the highest speed tiltback settings of any manufacturer (set it up to 30kph), and it looks like no upcoming competitor wheels will match that tiltback-on speed. 

[LorenW]

Hi Edwin -- Do you know if this true of the new Gotway ACM 16 as well?

[Cloud]

38 minutes ago, LorenW said:

Hi Edwin -- Do you know if this true of the new Gotway ACM 16 as well?

As far as i know gotway has not resolved the speed discrepancy yet, however, i believe they will issue the new app soon that will allow setting the tiltback speed higher than 30kph.

i was planning to run the real speed tests but the bike computer i ordered has not arrived yet

 

[edwin_rm]

7 hours ago, Cloud said:

As far as i know gotway has not resolved the speed discrepancy yet, however, i believe they will issue the new app soon that will allow setting the tiltback speed higher than 30kph.

i was planning to run the real speed tests but the bike computer i ordered has not arrived yet

 

Actually, in this thread the Gotway factory representative says that "maybe" they'll make an app in the future that allows for tiltback higher than 24 kph. So its not even in the plans! However, the real speed at that tiltback setting is 20 kph. In other words, max ACM tiltback speed is 20 kph, so barely anybody will ride with tiltback enabled. That is 10 kph slower than King Song. 

Gotways can be fast yes, however, they're not safe. I own/ride one, and have faceplanted due to max speed cutoff. Tiltback remains an afterthough for them.

[LorenW]

Wow... That will be very disappointing if GotWay does not address tiltback properly with the new ACM 16 and accompanying app(s).

[Cloud]

16 hours ago, edwin_rm said:

Actually, in this thread the Gotway factory representative says that "maybe" they'll make an app in the future that allows for tiltback higher than 24 kph. So its not even in the plans! However, the real speed at that tiltback setting is 20 kph. In other words, max ACM tiltback speed is 20 kph, so barely anybody will ride with tiltback enabled. That is 10 kph slower than King Song. 

Gotways can be fast yes, however, they're not safe. I own/ride one, and have faceplanted due to max speed cutoff. Tiltback remains an afterthough for them.

In that thread they said " maybe". However as far as i know they are addressing it already and updating the app for the acm to be able to set the tiltback speed far above 30

[UKJ]

The more I ride (about 500 Ks ) on my KS14c the more I trust it.

Other than the annoying over heat issue (which will hopefully be DIY made better soon) it just feels like it is solid, tough, and beeps, tilt back seem to be well thought out.

I am finding myself cruising at about 26 Km/hr and sometimes when want a little more speed push to my 28 first beep setting with confidence.

I have now ridden about 5 other brands and will say that 9B and Ips Xima feel ok while other off name cheaper ones feel MUCH less safe.

UKJ

[adhermes]

8 hours ago, UKJ said:

The more I ride (about 500 Ks ) on my KS14c the more I trust it.

Other than the annoying over heat issue (which will hopefully be DIY made better soon) it just feels like it is solid, tough, and beeps, tilt back seem to be well thought out.

I am finding myself cruising at about 26 Km/hr and sometimes when want a little more speed push to my 28 first beep setting with confidence.

I have now ridden about 5 other brands and will say that 9B and Ips Xima feel ok while other off name cheaper ones feel MUCH less safe.

UKJ

I have about 175 miles on my KS14C and yeah the overheat is annoying. However, I have about 190 miles on my MSUPER2. In my opinion it's not even close- I prefer to ride the MSUPER 100% of the time, and have designed the 14" as my "when friends come over they get to ride that one" wheel. 

 

I ordered the ACM16 because of how smooth and enjoyable the MSUPER ride is. Yeah the KS14C is super solid and has taken a freaking beating from me learning on it, but it's just not near as comfortable as the MSUPER.

[Jeffrey Scott Will]

14 minutes ago, adhermes said:

I have about 175 miles on my KS14C and yeah the overheat is annoying. However, I have about 190 miles on my MSUPER2. In my opinion it's not even close- I prefer to ride the MSUPER 100% of the time, and have designed the 14" as my "when friends come over they get to ride that one" wheel. 

 

I ordered the ACM16 because of how smooth and enjoyable the MSUPER ride is. Yeah the KS14C is super solid and has taken a freaking beating from me learning on it, but it's just not near as comfortable as the MSUPER.

If comfort is your reason for enjoying the Msuper so much, you may be disappointed with the ACM. It has the same pedals as the mcm4, which are significantly shorter. They're not bad, but certainly not Msuper comfy. 

[Chuts]

On 18/04/2016 at 5:01 AM, LorenW said:

Wow... That will be very disappointing if GotWay does not address tiltback properly with the new ACM 16 and accompanying app(s).

The eternal argument right there...

Kingsong made their wheels really safe.  Some people may argue they made it too safe and don't like all the forced hand-holding and because of this will think the KS16 as limiting.  However KS16 is more forgiving when you make those mistakes, almost everyone will agree that riding too over-confidently results in injury.

Gotway gives you all the power and speed but lacks the safety.  In a way people feel they are being treated more like adults and allowing you to ride unrestricted and leaves you to decide for yourself if you should push it.  All EU riders should know what happens if you do and the risk is up to oneself.

So you need to ask yourself are you someone who needs a wheel that can give you a second or even third chance when mistakes are made but restricting you of the full potential or if you require a wheel that is none restricting but you need to be constantly mindful of the speeds you ride and the how hard you push it.

[Cloud]

45 minutes ago, Chuts said:

The eternal argument right there...

Kingsong made their wheels really safe.  Some people may argue they made it too safe and don't like all the forced hand-holding and because of this will think the KS16 as limiting.  However KS16 is more forgiving when you make those mistakes, almost everyone will agree that riding too over-confidently results in injury.

Gotway gives you all the power and speed but lacks the safety.  In a way people feel they are being treated more like adults and allowing you to ride unrestricted and leaves you to decide for yourself if you should push it.  All EU riders should know what happens if you do and the risk is up to oneself.

So you need to ask yourself are you someone who needs a wheel that can give you a second or even third chance when mistakes are made but restricting you of the full potential or if you require a wheel that is none restricting but you need to be constantly mindful of the speeds you ride and the how hard you push it.

Very well said @Chuts. Two different approaches to safety. You mirror my thoughts exactly. As a novice i wanted to rely on the safeties of kingsong and that was very positive experience. Now that i have ridden about 3000km in difficult riding conditions and have seen just about all difficult riding scenarios, i want to have a chance to rely more on my experience of how to ride safely rather than some of the restrictions that are built in. I still like the fact that kingsong has a max tiltback speed at a more or less safe level, but i do understand gotway's approach too. For some people having a built in restriction is what they need to be safe, for others - knowing the restriction is not there will make them adjust their behavior and they will end up being safer.  Gotway hoever is working on making the tiltback speed adjustable to the upper 30s

[Tgellan]

In order to make the wheel, any wheel safer it doesn't need a speed limit, tilt back or what ever.

It needs:

 - Redundancy on critical parts, such that a technical problem while running won't result in a faceplant. (financial problem)

 - Batteries that are able to support the asked current during the whole discharge curve (engineering problem)

 - A display showing not 2,4,10 bars for battery, but remaining Wh in human readable numbers

 - A gauge that shows how close to max power/torque you are

 - A user accessible black box for evaluating a ride, showing how close you came to a situation

And best would be

 - Having the critical information  permanently at disposal, without having to look down at the wheel, or the phone. Thus what we need is some kind of HUD...

T'Gellan

[esaj]

3 hours ago, Tgellan said:

 - A display showing not 2,4,10 bars for battery, but remaining Wh in human readable numbers

Personally I prefer voltage display. The amount of "remaining Wh" will vary according to the power output, you actually get less Wh out from the pack with high discharge than low discharge. Check the discharge curves for the cells from something like http://www.dampfakkus.de/ , you'll notice that the total amount of Ah (and thus, Wh) is different depending on the discharge current. Voltage does not "lie".

[Tgellan]

On 14/6/2016 at 10:53 AM, esaj said:

Personally I prefer voltage display. The amount of "remaining Wh" will vary according to the power output, you actually get less Wh out from the pack with high discharge than low discharge.

Well, I was discussing "make the wheel safer" thus for the general public. Those people need a reliable and most importantly a LINEAR way of telling how much juice they got left. Voltage is by no way a linear way of telling. I agree with you that voltage is the value to measure, but it has not to be the value that is shown.

What I mean, the problem is a engineering problem, "all" you have to do is look at a combination of several values and compute the needed information. It's actually what yourself are doing by looking at the Voltage. You know that for that given batterypack a certain voltage equals a certain number of Wh. But that could be done by the wheel too! It has to measure the Wh over multiple charge cycles and show the best estimation for the current voltage. That way, if the battery degrades the shown numbers would reflect it.

One could / should take it even one step further, as I guess even Wh is not the right information the normal user needs during the ride. What he needs is a condition adapted estimation on the remaining range in km. Conditions adapted means, at the current riding conditions (thus load and driving resistance, or in units, average A or Wh per km), and based on historical data for the given battery pack. This is actually done in my EV which does show me this estimated range, if it shows me some 5km left, for normal conditions that is true. If at that moment I change my driving style, the estimation is off, but it will adapt. The same is true if the profile changes due to hills vs flatland or night vs day (headlights) or even sunny vs rain, it just reads the current average consumption for a given speed/range, computes in the historical data and shows a "best guess".

So long

T'Gellan

[UKJ]

 

On 4/21/2016 at 5:42 PM, adhermes said:

 but it's just not near as comfortable as the MSUPER.

Any chance you could go into more detail on what you mean by comfortable compairing the 2 please.

ukj

[Sam LaRoche]

Not sure if the KS is "safer" than other models but I can tell you from experience, the KS can fail without warning from a low battery condition. I had originally purchased a 540WH KS-18A and tried to ride it the 18.5 mile trip to work and back. At about 1/4 of a mile from the destination, it died. No warning beeps or tilt back. Wasn't pleasant. Then decided to make sure I charged after every ride (~9 miles). After a few weeks, a wire came loose and the battery display showed more life than what was actually available. Again it cut out w/o warning of any sort. I've now upgraded to 680 Wh of battery so I can safely go round trip w/o much fear of a low battery condition. My suggestion is to not run the battery anywhere near no remaining power. I also wear elbow and wrist guards for any distance riding. I've wrecked at full speed w/o either and luckily I am a pretty good tumbler and escaped with only a couple scrapes. One could easily loose a few teeth if you don't know how to tuck and roll. Either way, after 4 wrecks at full "unlocked" speed (~20 MPH), I can say that wrecks on a EU should be avoided all together!