Another KS 16X cut off - don't ride KS16X at the higher speeds! (gross photo warning)

[photorph]

In all my time of riding EUCs and riding 10+ different EUCs, I've never experienced a cut out or a fall at such high speed.  With the KS 16X I had a cut out at 27.8 mph, no beeps or tilt-back as I had those set to 29 mph and 30 mph respectively per the top speed listed by KS.  Post cut off voltage was 77v.  There really was no reason for a cut off here, I'm only 145 lbs and was riding at a sufficient battery (77v), temperature was around 50F, and I'm on the latest firmware 1.07.  Cut out happened when I attempted to accelerate from 27 to 29 with a gentle push.  

I'm 100% okay with the exception of this road rash on left side where my jacket lifted up, second day and it's running it's cycle of healing.  I'll be perfectly okay.  Many thanks to Alpinestar motorcycle jacket/Klim K fifty 2 moto jeans/knox gloves.  Just a flesh wound that will heal soon.  

 

Making this post as a PSA.  On the KS16X recommend setting 3rd alarm to 40-42 km/h and tilt-back to around 43-45 km/hr.  These are the max speeds kingsong should have advertised rather than trying to match the nikola.  I'm also wondering another thing, will it cut out at slower speeds on a steep hill climb...

There's another long thread on this here with someone who also cut out at a similar speed:

https://forum.electricunicycle.org/topic/16436-ks16x-cutoffoverlean-29-30mph/

 

I will add that kingsong has new controllers that are a different design than the one I had on my second batch KS16X.  Will this mean that the you actually will have power reserves at 25+ mph to avoid a cut out??  That I cannot say, but I won't be the one to attempt to push it once above 25 mph even if I put in the new controller.  Or I might just sell the wheel, as I can't keep up with 100v gotway group rides.

 

Edited December 26, 2019 by photorph

[ir_fuel]

Good you were wearing gear!

I've always considered 25mph the max on this wheel.

[EUC Custom Power-Pads]

4 hours ago, photorph said:

I will add that kingsong has new controllers that are a different design than the one I had on my second batch KS16X.  Will this mean that the you actually will have power reserves at 25+ mph to avoid a cut out??  That I cannot say, but I won't be the one to attempt to push it once above 25 mph even if I put in the new controller.  Or I might just sell the wheel, as I can't keep up with 100v gotway group rides.

When I think back to my version 1.4 Control Board, I also have to say that I didn't feel very comfortable at 25mph+ due to some dicey situations with bumps.

Since Control Board V1.5 it is a different wheel and riding full speed feels very safe since then.

I hope I don't have to correct my statement soon.  

[alex5454]

12 minutes ago, buell47 said:

When I think back to my version 1.4 Control Board, I also have to say that I didn't feel very comfortable at 25mph+ due to some dicey situations with bumps.

Since Control Board V1.5 it is a different wheel and riding full speed feels very safe since then.

I hope I don't have to correct my statement soon.  

hi how do i know which card i have?

I bought KS 16X from aliexp (lot of August Taurus) with chaoyang tire H-5167 ... I'm really so afraid of cut-off ... even if I put it tiltback 40km/h. I have firmware 1.0.7

Edited December 26, 2019 by alex5454

[photorph]

20 minutes ago, buell47 said:

When I think back to my version 1.4 Control Board, I also have to say that I didn't feel very comfortable at 25mph+ due to some dicey situations with bumps.

Since Control Board V1.5 it is a different wheel and riding full speed feels very safe since then.

I hope I don't have to correct my statement soon.  

Did you try to accelerate quick at higher speeds?  Example going from 26-30 mph quickly?  

 

Did you try an ankle flick?  If this happens, then issue is not solved.  See two below:

 

 

 

Edited December 26, 2019 by photorph

[EUC Custom Power-Pads]

16 minutes ago, photorph said:

Did you try to accelerate quick at higher speeds?  Example going from 26-30 mph quickly?  

 

Did you try an ankle flick?  If this happens, then issue is not solved.  See two below:

I know the Ankle flicks, but didn't feel the need to test this one. I ride fast and I also ride fast offroad through potholes, over roots and through bumps and since Control Board V1.5 I haven't had any situations where I noticed the wheel tilted forward for a short time.

But I had such experiences several times with V1.4 at much slower rides and smaller bumps.

Accelerations from 40 to 47- 50 kmh were also there, but except for 4 beeps (overpower alarm) and soft tilt back everything was as expected. I think I know my wheel quite well by now and know how far I can go when accelerating. No Micheal Jackson style.

I weigh 78kg dressed. 

[EUC Custom Power-Pads]

31 minutes ago, alex5454 said:

hi how do i know which card i have?

I bought KS 16X from aliexp (lot of August Taurus) with chaoyang tire H-5167 ... I'm really so afraid of cut-off ... even if I put it tiltback 40km/h. I have firmware 1.0.7

I do not know whether it could be determined here in the meantime due to the serial numbers. Otherwise the wheel must be opened to look at the board. 

[redfoxdude]

I'm glad you are okay! I'm very disappointed that King Song has remained pretty much silent on this. My cut off was with the newer v1.5 board. The ankle flick issue wasn't resolved for me with the newer board, unfortunately...

[alex5454]

8 hours ago, photorph said:

In all my time of riding EUCs and riding 10+ different EUCs, I've never experienced a cut out or a fall at such high speed.  With the KS 16X I had a cut out at 27.8 mph, no beeps or tilt-back as I had those set to 29 mph and 30 mph respectively per the top speed listed by KS.  Post cut off voltage was 77v.  There really was no reason for a cut off here, I'm only 145 lbs and was riding at a sufficient battery (77v), temperature was around 50F, and I'm on the latest firmware 1.07.  Cut out happened when I attempted to accelerate from 27 to 29 with a gentle push.  

I'm 100% okay with the exception of this road rash on left side where my jacket lifted up, second day and it's running it's cycle of healing.  I'll be perfectly okay.  Many thanks to Alpinestar motorcycle jacket/Klim K fifty 2 moto jeans/knox gloves.  Just a flesh wound that will heal soon.  

 

Making this post as a PSA.  On the KS16X recommend setting 3rd alarm to 40-42 km/h and tilt-back to around 43-45 km/hr.  These are the max speeds kingsong should have advertised rather than trying to match the nikola.  I'm also wondering another thing, will it cut out at slower speeds on a steep hill climb...

There's another long thread on this here with someone who also cut out at a similar speed:

https://forum.electricunicycle.org/topic/16436-ks16x-cutoffoverlean-29-30mph/

 

I will add that kingsong has new controllers that are a different design than the one I had on my second batch KS16X.  Will this mean that the you actually will have power reserves at 25+ mph to avoid a cut out??  That I cannot say, but I won't be the one to attempt to push it once above 25 mph even if I put in the new controller.  Or I might just sell the wheel, as I can't keep up with 100v gotway group rides.

 

at what pressure bar did you drive? how can i avoid this you were in expert mode?
I use in medium mode with 2 alarm 35 km/h and 3 alarm 38 km/h, tilt back at 40 km / h (I have 1.07 firmware). you're making me worry.

[photorph]

7 hours ago, redfoxdude said:

I'm glad you are okay! I'm very disappointed that King Song has remained pretty much silent on this. My cut off was with the newer v1.5 board. The ankle flick issue wasn't resolved for me with the newer board, unfortunately...

When did you get your replacement control board again?  The 3rd KS16X batch and newer design control boards are a recent thing in the US.  If your KS16x was first or second batch (mine is 2nd), then it didn't have the updated control board.  

 

3 hours ago, Aneta said:

I must be missing something... This is a known scenario, why repeat it?

Because...for science.  I still have to repeat it with the new control board and see if it persists.  But really, kingsong should just limit the wheel to 25 ish mph rather than 30 mph.  

 

4 hours ago, alex5454 said:

at what pressure bar did you drive? how can i avoid this you were in expert mode?
I use in medium mode with 2 alarm 35 km/h and 3 alarm 38 km/h, tilt back at 40 km / h (I have 1.07 firmware). you're making me worry.

30 PSI, perfectly good pressure for my weight.  I was in experient/hard mode.  Turn first and second alarm to zero.  For 3 and 4 if you have 38 and 40k you will be fine.  I had 49 and 50.  Now I changed it to 40 and 42 for tilt back.  I think even these are safe, and yours are more conservative so don't worry.  

Edited December 27, 2019 by photorph

[alex5454]

6 hours ago, photorph said:

When did you get your replacement control board again?  The 3rd KS16X batch and newer design control boards are a recent thing in the US.  If your KS16x was first or second batch (mine is 2nd), then it didn't have the updated control board.  

 

Because...for science.  I still have to repeat it with the new control board and see if it persists.  But really, kingsong should just limit the wheel to 25 ish mph rather than 30 mph.  

 

30 PSI, perfectly good pressure for my weight.  I was in experient/hard mode.  Turn first and second alarm to zero.  For 3 and 4 if you have 38 and 40k you will be fine.  I had 49 and 50.  Now I changed it to 40 and 42 for tilt back.  I think even these are safe, and yours are more conservative so don't worry.  

30 psi = 2.0 bar .... i use 43 psi = 3.0 bar on ks 16x .... V10 3.2 bar and One s2 3.4 bar.....

how much can the pressure of the wheel affect what happened?

[EUC Custom Power-Pads]

6 hours ago, Aneta said:

There can't be any well-defined speed limit for any wheel. Due to inherent property of BLDC motors (approx. linearly reducing torque with speed until zero torque at no-load speed) and inherent property of aerodynamic drag increasing proportionally with square of speed, and inherent inertial force of acceleration (accelerating 145lbs + ~55lbs of wheel and gear = 200lbs total at a gentle 0.05g (that's only 0.8 mph per second) requires additional 200*0.05 = 10lbs of thrust the motor may not have at ~25+mph; same for a very gentle, virtually invisible bump with only 5% slope (20 inches long, only 1 inch rise)), at high speeds we're essentially talking about walking on thin ice that's cracking under our feet. We're walking towards the edge where ice diminishes to zero thickness. How far can we go? There can't be a well-defined boundary, because it depends on so many factors. At the very least, we should heed to warnings from other "thin ice walkers" who went too far.

Oh no, please do not fill the thread again with mathematical and physical calculations. We already have quite a few of those. 

This is known, why repeat it?

[photorph]

8 hours ago, Aneta said:

There can't be any well-defined speed limit for any wheel. Due to inherent property of BLDC motors (approx. linearly reducing torque with speed until zero torque at no-load speed) and inherent property of aerodynamic drag increasing proportionally with square of speed, and inherent inertial force of acceleration (accelerating 145lbs + ~55lbs of wheel and gear = 200lbs total at a gentle 0.05g (that's only 0.8 mph per second) requires additional 200*0.05 = 10lbs of thrust the motor may not have at ~25+mph; same for a very gentle, virtually invisible bump with only 5% slope (20 inches long, only 1 inch rise)), at high speeds we're essentially talking about walking on thin ice that's cracking under our feet. We're walking towards the edge where ice diminishes to zero thickness. How far can we go? There can't be a well-defined boundary, because it depends on so many factors. At the very least, we should heed to warnings from other "thin ice walkers" who went too far.

Well...all this explanation isn’t necessary.  They should just lower the max to 25 mph.  That would prevent cut outs for most people because at that speed it has enough power reserves.  A Gotway 100v on the other hand will be fine at 30 mph.  
 

so yes there cannot be any well defined speed, but there can be a speed at which the motor and electronics are working below their spec and it’s safe to push it and not overwhelm it.

2 hours ago, alex5454 said:

30 psi = 2.0 bar .... i use 43 psi = 3.0 bar on ks 16x .... V10 3.2 bar and One s2 3.4 bar.....

how much can the pressure of the wheel affect what happened?

Very little, I ride my Gotway 100v at less than 3 bar and can hit 30+ and push it with no cut outs or pedals dips even if I push hard.  
 

my beef with this wheel is...just lower the speed limit.  It’s a 25 mph wheel, just like the v10F.

[Rehab1]

23 hours ago, photorph said:

  Just a flesh wound that will heal soon.  

UGH! I’m pleased your (fairly) ok! Thanks for the ‘Gross Photo’ warning! Unfortunately I have a tendency to gravitate to unpleasant posts. So glad I waited until after breakfast. 

Edited December 27, 2019 by Rehab1

[Brandin J. Mercer]

I just ordered this wheel, and I gotta say im a lil nervous with all the stories of cuttoffs, but then agian I have 0 intention of goin over 25mph. So hopefully i should be fine. I like to cruise between 14-18mph. I mainly got this wheel so I can go 25 miles worry free that that battery wont run out or be throttled to 11mph. probably overkill but yea. 

Glad ya ok!

[EUC Custom Power-Pads]

My intention was in April 2019:

Hey, what's that? A unicycle and electric too?

Wow, that would be a nice toy to have some fun in the garden or to ride up and down the path in front of the house while my daughter learns to ride a bike.

Now I'm praying that something off-road suitable will come out next spring with at least 40 mph+, 60 miles range at least 25 mph AVG speed and what might not look as cheap as a Gotway MSX. (sorry to all MSX owners) 

But probably for the first time in my life I would even buy something that I don't like optically, if the technical wishes are fulfilled.

[mrelwood]

14 hours ago, Aneta said:

There can't be any well-defined speed limit for any wheel. Due to inherent property of BLDC motors

...

Yes there can. And KingSong has been quite good setting them in the past. Overleans on a 16S, 18S, or 18XL are quite rare cases because those wheels have a reasonable reserve at their max speed.

A KingSong rider has previously been able to trust that the wheel is relatively safe to use at the maximum speed it can go. The 16X changed all that. The max speed is 50km/h, but the wheel is clearly not capable for the max speed with a reasonable thrust margin. The wheel has been said to lose it’s power at 40km/h (or slightly above). But I don’t think KingSong users can be expected to lower their wheels’ top speed due to postings on a discussion forum. The manufacturer that has long been considered to be ”the safe choice” should’ve done that properly before shipping the wheel.

But a 40km/h top $ wheel in 2019 just doesn’t cut it, so they decreased the safety margin too much. Top speed of 40km/h would’ve turned many buyers to a Gotway, which doesn’t have this ”inherent problem of BLDC motors” until at much faster speeds.

And nobody buys a Gotway expecting it to limit the rider’s top speed to safe levels. They have never done that, and probably never will. Funny thing is, they are still the safest wheels at 50km/h because of the speed and thrust reserves. But it’s still up to the rider to limit the top speed, by setting the tilt-back at it’s maximum of 49km/h or otherwise.

Edited December 27, 2019 by mrelwood

[alex5454]

2 minutes ago, mrelwood said:

Yes there can. And KingSong has been quite good setting them in the past. Overleans on a 16S, 18S, or 18XL are quite rare cases because those wheels have enough reserve at their max speed.

A KingSong rider has previously been able to trust that the wheel is relatively safe to use at the maximum speed it can go. The 16X changed all that. The max speed is 50km/h, but the wheel is clearly not capable for the max speed with a reasonable thrust margin. And I don’t think KingSong users can be expected to lower their wheels’ top speed due to postings on a discussion forum. The manufacturer that has long been considered to be ”the safe choice” should’ve done that properly before shipping the wheel.

But a 40km/h top $ wheel in 2019 just doesn’t cut it, so they decreased the safety margin too much. Top speed of 40km/h would’ve turned many buyers to a Gotway, which doesn’t have this ”inherent problem of BLDC motors” until at much faster speeds.

And nobody buys a Gotway expecting it to limit the rider’s top speed to safe levels. They have never done that, and probably never will. Funny thing is, they are still the safest wheels at 50km/h because of the speed and thrust reserves. But it’s still up to the rider to limit the top speed, by setting the tilt-back at it’s maximum of 49km/h or otherwise.

I honestly don't care about the top speed of 50 km / h. I just don't want to have a cut off when I'm traveling if I put 40 km / h on KS 16x can I sleep peacefully ?

[mrelwood]

 

1 minute ago, alex5454 said:

if I put 40 km / h on KS 16x can I sleep peacefully ?

Absolutely probably! The 40km/h seems to be the recommended speed limit by the ones who have overleaned, so my understanding is that you would be as safe as can be expected on an EUC. Especially with the 1.07 firmware.

[travsformation]

9 hours ago, mrelwood said:

Yes there can. And KingSong has been quite good setting them in the past. Overleans on a 16S, 18S, or 18XL are quite rare cases because those wheels have a reasonable reserve at their max speed.

A KingSong rider has previously been able to trust that the wheel is relatively safe to use at the maximum speed it can go. The 16X changed all that. The max speed is 50km/h, but the wheel is clearly not capable for the max speed with a reasonable thrust margin. The wheel has been said to lose it’s power at 40km/h (or slightly above). But I don’t think KingSong users can be expected to lower their wheels’ top speed due to postings on a discussion forum. The manufacturer that has long been considered to be ”the safe choice” should’ve done that properly before shipping the wheel.

But a 40km/h top $ wheel in 2019 just doesn’t cut it, so they decreased the safety margin too much. Top speed of 40km/h would’ve turned many buyers to a Gotway, which doesn’t have this ”inherent problem of BLDC motors” until at much faster speeds.

And nobody buys a Gotway expecting it to limit the rider’s top speed to safe levels. They have never done that, and probably never will. Funny thing is, they are still the safest wheels at 50km/h because of the speed and thrust reserves. But it’s still up to the rider to limit the top speed, by setting the tilt-back at it’s maximum of 49km/h or otherwise.

👏 👏 👏 

Very well put. I've been meaning to say something exactly in those lines for some time but have been too lazy to go to the trouble of putting it in words 😅

I couldn't agree more! The King of safety has shot itself in the foot trying to compete directly with the Nikola... 

Edited December 28, 2019 by travsformation

[travsformation]

23 hours ago, buell47 said:

I know the Ankle flicks, but didn't feel the need to test this one. I ride fast and I also ride fast offroad through potholes, over roots and through bumps and since Control Board V1.5 I haven't had any situations where I noticed the wheel tilted forward for a short time.

But I had such experiences several times with V1.4 at much slower rides and smaller bumps.

Accelerations from 40 to 47- 50 kmh were also there, but except for 4 beeps (overpower alarm) and soft tilt back everything was as expected. I think I know my wheel quite well by now and know how far I can go when accelerating. No Micheal Jackson style.

I weigh 78kg dressed. 

My 16X should be arriving any day now. I'm not sure which batch it is...3rd or...is there a 4th? I know it shipped from China on an "express" train almost a month ago, so it's the latest batch. Can't wait to get it!

I'm not a speed daemon, I do most of my riding off-road, where I rarely go over 30-35 km/h (18-21 mph), and when riding around the city, the bike lanes are in terrible condition and there are very few stretches where I can ride above 40 km/h / 25 mph. I'm not an excessively aggressive rider, although more so when off-roading. I weigh exactly the same as you fully geared.

What do you have speed alarms and tiltback set to? Any particular safety considerations I should take into account ("careful when accelerating above X speed", etc.)?

Also, what pressure do you use? I see that @photorph uses 30 psi, which seems very low to me (I know some people like cushier rides), as I run my 18XL on 42 psi.

BTW, @photorph, glad you're OK!!!

 

Edited December 27, 2019 by travsformation

[RockyTop]

7 hours ago, buell47 said:

Oh no, please do not fill the thread again with mathematical and physical calculations. We already have quite a few of those. 

This is known, why repeat it?

 ........ well? ... I’m out.  

      The 27 MPH 16X curse. 

@photorph I am glad you were not hurt badly. Thank you for your PSA and information. 

[EUC Custom Power-Pads]

31 minutes ago, travsformation said:

I'm not a speed daemon, I do most of my riding off-road, where I rarely go over 30-35 km/h (18-21 mph),

Yes, that's how it looked for me in summer when the forests were still ridable. When it became too muddy it went unexpectedly on public roads (although illegal here). 

In addition the enormous range, the next city was reachable, the distances became longer. 

This has led to the fact that 50kmh is no longer enough for me, because on good tracks I often ride at the limit. 

31 minutes ago, travsformation said:

What do you have speed alarms and tiltback set to? 

1st and 2nd Alarm is off, 3rd Alarm at 45kmh and tilt back now at 47 kmh (because cold temperatures). If it's warmer I set it to Alarm 47 and tilt back 50kmh. 

31 minutes ago, travsformation said:

Any particular safety considerations I should take into account ("careful when accelerating above X speed", etc.)?

Above 40 kmh simply do not exaggerate. 

 

36 minutes ago, travsformation said:

Also, what pressure do you use? I see that @photorph uses 30 psi, which seems very low to me (I know some people like cushier rides), as I run my 18XL on 42 psi.

On tricky offroad trails I felt most comfortable at 20 psi.

But after that ....

....I raised the pressure to 26 psi for offroad use. 

Now I'm on 30 psi for normal street use. 

 

[Xolition]

If you don't trust the wheel, sell it. Life is too short.

[Mike Sacristan]

Sorry to hear about your crash @photorph and happy to see you made it out with "just a scrape".

If it's of any interest I have my 3rd alarm at 45 kmh and tilt-back at 50kmh.
I rarely hit hard tilt-back but I am usually gently on soft tilt-back.
As my ride progresses and the battery goes down soft tilt-back comes at a lower speed.

The alarm is set to 45 just so that I am aware to not do any crazy leaning at that speed.
Sometimes when I am riding on soft tilt-back and I push the pedals to hard I get the 88% alarm (4 quick beeps).
Maybe once or twice I have pushed so hard that I got 4 quick beeps and hard tilt-back but I was asking for it.

Were there any inclines or potholes involved in this accident?
I feel that my 16X (1st batch FW 1.07) has always been very good at presenting soft tilt back and thus making it reasonably difficult for me to push it further.
My riding weight now that it's winter is 155 lbs (70kg).
Yesterday I went for a 36km ride and spent the 18km back home pretty much beeping until I hit soft tilt-back at 44kmh. I only slowed down for parts that were too dark, as I wouldn't want to stumble forward on soft tilt-back because of an unseen obstacle or irregularity in the road.
When I got home the 16X was at 71V which later recovered to 72V. Temperature was -1C.

3680km on the wheel. Experient mode and 25 PSI.

Have you had any other problems with the wheel?