HEC Posted July 21, 2016 Share Posted July 21, 2016 So after riding the new KS16 over month and about 900 Km so far without any issues I've had the wheel to fail / fold under me twice this week First fold happened on Monday morning on the way to work. My commute consist of two parts ride with train trip in middle. First part from home to train station (about 2 Km) went without a hitch. The wheel was charged previous evening to 87% using Charge Doctor set to cut of charging at 66.4V. After exiting the train I've switched the wheel on, pulled out the trolley handle and pushed it up the (flat) escalator, across the hall and crosswalk exactly as any other day. At my "take of point" I've unfolded the pedals, zipped up the jacket and put on the bicycle bell on my hand. While commuting I usually use the "standing" take off as I'm still not 100% capable to do the normal step up / running start on KS so I lean against the traffic light post conveniently located at my take off point, position my feet comfortably and once the green light pops I'll lean very mildly forward to cross and start rolling. I've done this a hundred times before with zero issues. However this time wheel simply folded under me once I've let go of the post! I've fell forward, wheel shoot backwards from under me and tipped on side (and get scratched to upset me even more). No beeps, no warnings - nothing. I always ride with lights on so every time I switch on the wheel I'll change the light mode from Auto to On via mobile app (please KS change this!) being greeted by loud "Hello KingSong!" voice prompt (despite having the voice prompts turned off - again KS please fix this!) after which I'll again turn the voice off. At first I thought that maybe I've over-leaned the wheel way to much to either of the sides while unfolding the pedals but thinking about that later on it's unlikely for two reasons: 1. There was no warning beep and 2. Wheel was still powered on and tire was spinning after it slipped from under me without balancing and fell of on it's side! (at which time the tip over alarm sounded). I've restarted the wheel and took of as I was about to be late to work if I'd need to fiddle around more. I've not checked the temperature but the wheel was resting after the first part of the commute for about 25 minutes and battery was at 83%. Ambient temperature was about 15 Degrees C. Rest of the day and Tuesday the wheel behaved again though my trust in it was a bit shaken. All was good until yesterday afternoon. While all 4 commute trips went fine same happened at start of my leisure afternoon ride after work. After getting home from work I've put the wheel on charger to top it up a bit (to about 66.6V). I always let the wheel to cool down before and after charging. Then I've carried it down the stairs, switched it on and pushed it a bit across the road to my favourite take off spot next to the traffic sign post which I lean against. And exactly the same - mild lean to front after positioning the feet and wheel folded! No beeps, no warning, no excessive acceleration. As I was already weary since the Monday's incident I was using the "training" belt and was able to catch the wheel keeping it from tipping over and hitting ground again this time. What's most interesting that wheel was still on and balancing again without need to power cycle it. Just to be on the safe side I have restarted it and took of very carefully ... After this second incident it was behaving again - I've rode it the whole afternoon on the beach walk and in the harbour for about 2 and half hours non stop until the battery was depleted to 6% (video upcoming - once I'll figure out how to join 3 MP4 video files together - it's uploaded now and YT is chewing on it to produce HD version, currently only 360P poo is up ... ) and it also behaved today morning on the way to work. My trust in the wheel though is fairly shaken and I'm now worried every time I'm stopping at crossings / traffic lights that it might happen again any time while taking off from standing position This is really dangerous behaviour and should never happen on functional wheel! I don't know if @Jason McNeil can pass this to KingSong for comments? I'm still on FW v1.19 as shipped. Ride mode set to Player. Prior those two incidents the wheel was not in any crash or even drop. It was ridden only on smooth surface tarmac on bicycle lanes, not jumping any curbs or doing any extreme tricks or riding at all. I remember one or two forum members here in forums mentioning previously "overpower" warnings with older versions of the FW - maybe this is related? And yes - I do check that wheel is actually balancing every time I switch it on - before (by hand) and after I step on it. It was definitely balancing right prior each of both incidents. It looks to me like while you shuffling around on the wheel in stationary position and wheel changes the directions / light several times it might get "confused" in some situation and simply not react quickly / correctly to riders lean input for take off. EDIT: Also mentioned by @johrhoj in this thread: Link to comment Share on other sites More sharing options...
US69 Posted July 21, 2016 Share Posted July 21, 2016 @HEC As i have said in other threads...i have a new KS18.... on my very First ride Outside...exactly the same happend to me. i allready tried the wheel inside my living room....bring it outside with power off...powered it on...proofed the stability like always.... but left feet on it...grab to a pole...put right feet on it.....want to start... And fell of...curious: i step off in front...as the wheel had not balanced me and turned myself to the wheel: i still saw it standing and balancing with power and could clearly see how it then slowly falls to the side...scratched :-( so power was there...just seems not enough to balance me Beside, that i thought: good start for a new wheel...i DID HEAR of something like that before and was warned: @johrhoj you want to comment also? so for me it seams like a Firmware glitch, as i am in 1.20....one which seams to be in 1.19 then also.... this only happend to me this one time..but since then, i always start with it more like a roller, so that the wheel has in one direction a little bit moving...what i heard...this only happends on totally still start and when standing in a small ditch... as like the wheel did not know in which direction to move and then decides to do none! the "overpower" problem from before version.....the wheel was not folding under you...just screaming at hard rocking starts.... Link to comment Share on other sites More sharing options...
EricGhost Posted July 21, 2016 Share Posted July 21, 2016 I'm sorry for your injuries, I hope they are minor ones As a newby wheeler and owner of a new KS16 680Wh, your experience is scaring the hell out of me as the trust in the wheel is mandatory for a proper balancing. You look (like me but I've 1.2 FW) to be a conservative user of your wheel; you take care either in the charging phase and in the driving one with no rush accelerations, so I hope it is not just mere luck that both foldings occured at the start, I cannot think what will become of me if something like you told us happens while I'm on speed 15-25 Kmh and ,worst of all, on the track lane of my commute in the park with gravel everywhere. Let's hope it is something defective in your wheel and related only to the initial motion, and not an embedded KS16 production problem !! Please update as soon as you have more infos Link to comment Share on other sites More sharing options...
Chriull Posted July 21, 2016 Share Posted July 21, 2016 This happened to me on my KS16 about 3 times in total. I weigh around 90kg and i prefer to start driving from standstill. My brother with ~20kg less and making "flying starts" never had this prob... Link to comment Share on other sites More sharing options...
HEC Posted July 21, 2016 Author Share Posted July 21, 2016 4 hours ago, KingSong69 said: but left feet on it...grab to a pole...put right feet on it.....want to start... And fell of...curious: i step off in front...as the wheel had not balanced me and turned myself to the wheel: i still saw it standing and balancing with power and could clearly see how it then slowly falls to the side...scratched :-( I'll just repost my text from another thread: What I suspect is happening that when you "stop" you might be intermittently putting the wheel in the "reverse" and back and that's what I believe is the culprit here. The code responsible for the detection of the "forward" movement must be glitching at some specific point of that almost stand-still moment while the directions are being swapped. I doubt it's the hardware issue or issue with motor or battery not having enough "power" as battery was almost fully charged, initial speed was zero and acceleration / lean very mild so that will not have any chance to cause the overload. This is very serious and worrying issue and I'm loosing trust in my EUC due that 3 hours ago, EricGhost said: You look (like me but I've 1.2 FW) to be a conservative user of your wheel; you take care either in the charging phase and in the driving one with no rush accelerations, so I hope it is not just mere luck that both foldings occured at the start, I cannot think what will become of me if something like you told us happens while I'm on speed 15-25 Kmh and ,worst of all, on the track lane of my commute in the park with gravel everywhere. Let's hope it is something defective in your wheel and related only to the initial motion, and not an embedded KS16 production problem !! As per my comment above I doubt it's faulty wheel. It really looks like software / firmware issue to me and happens only during "standing" start take offs. Once you're moving this will not have effect on your wheel so you're not in danger of falling at high (or even low) speed as long as your wheel moves. So technically lesser of two evils - better to drop from standstill than at (high) speed - but indeed even better is to NOT drop at all! 3 hours ago, Chriull said: This happened to me on my KS16 about 3 times in total. I weigh around 90kg and i prefer to start driving from standstill. My brother with ~20kg less and making "flying starts" never had this prob... What I'm doing for now since the second incident is that I push myself of the pole or whatever else I'm holding onto while standing before I let go but that's not always possible or at least safe due to the placement or distance of the "hold on" objects from the ridable surface. Link to comment Share on other sites More sharing options...
US69 Posted July 21, 2016 Share Posted July 21, 2016 3 minutes ago, HEC said: I'll just repost my text from another thread: What I suspect is happening that when you "stop" you might be intermittently putting the wheel in the "reverse" and back and that's what I believe is the culprit here. The code responsible for the detection of the "forward" movement must be glitching at some specific point of that almost stand-still moment while the directions are being swapped. I doubt it's the hardware issue or issue with motor or battery not having enough "power" as battery was almost fully charged, initial speed was zero and acceleration / lean very mild so that will not have any chance to cause the overload. This is very serious and worrying issue and I'm loosing trust in my EUC due that as i am quit good in idling on a point...and comming to a standstill while driving, with new start ( i am very often with my dog and have to wait) ...i can assure you...that at least until now..this never happends "while" riding...just if you start from stand still. so for me it seams a little different then the "low cut outs" of the ACM....what tremf described on his fail i am doing the hole day on my wheel... Also "Johrhoj", from him i got this warning, described it as a glitch on pure "standstill-then starting with balast" glitch...like chriull also... sure its a serious bug and needs to be adreesed!! but i think as long as you give the wheel the first direction by moving to one side, you will not experience it again....i even hope so!! 5 minutes ago, HEC said: What I'm doing for now since the second incident is that I push myself of the pole or whatever else I'm holding onto while standing before I let go but that's not always possible or at least safe due to the placement or distance of the "hold on" objects from the ridable surface. with this push off, you should not get the fault again...i hope you will not get that fault again... Link to comment Share on other sites More sharing options...
EricGhost Posted July 21, 2016 Share Posted July 21, 2016 22 minutes ago, HEC said: As per my comment above I doubt it's faulty wheel. It really looks like software / firmware issue to me and happens only during "standing" start take offs. Once you're moving this will not have effect on your wheel so you're not in danger of falling at high (or even low) speed as long as your wheel moves. So technically lesser of two evils - better to drop from standstill than at (high) speed - but indeed even better is to NOT drop at all! indeed no folding wheels at all!!!!!!! Link to comment Share on other sites More sharing options...
Keith Posted July 21, 2016 Share Posted July 21, 2016 It certainly looks like this problem is very specific to the KS-16 and 18. I have heard no reports of this on the KS-14 and, indeed I have so much street furniture where I live that I've got lazy and very rarely ever do an unsupported start as there is always a bollard, lamppost, traffic light, etc. wherever I need to stop thus saving me ever needing to dismount. My 500W KS-14 has never shown any sign of this happening. I have (I think) overleaned on take off a few times, particularly when starting uphill and the wheel sort of makes almost a grinding noise that warns me I've overdone it but it has always continued to accelerate away OK. The reason I mention all of the above, is that if the KS-14 does not suffer from this problem then KingSong ought to have a fairly good idea what (if anything?) they have changed in the KS-16/18 hardware/firmware that could possibly cause this - unless, of course the problem is directly the result of those wheels being larger? By the above I mean that one worrying theory (IMHO) is that a higher power, higher top speed motor, if it is physically no bigger than the motor it supercedes must necessarily have lower torque at zero speed as it needs less turns of thicker windings to achieve more power and more speed. That both reduces torque and can result in significantly higher current demand on acceleration from zero which would make the motor less effective at zero speed and the larger moment arm of the bigger 16" and 18" wheels would amplify the problem, possibly explaining why it isn't being seen on even the higher power KS-14? Link to comment Share on other sites More sharing options...
HEC Posted July 21, 2016 Author Share Posted July 21, 2016 20 minutes ago, Keith said: By the above I mean that one worrying theory (IMHO) is that a higher power, higher top speed motor, if it is physically no bigger than the motor it supercedes must necessarily have lower torque at zero speed as it needs less turns of thicker windings to achieve more power and more speed. That both reduces torque and can result in significantly higher current demand on acceleration from zero which would make the motor less effective at zero speed and the larger moment arm of the bigger 16" and 18" wheels would amplify the problem, possibly explaining why it isn't being seen on even the higher power KS-14? I don't really think this is down to motor power or torque or issues with battery or any other bit of HW. It feels like software bug / problem though it might be related to different hall sensors, positions of the magnets or amount of windings etc. but that's all speculations without going down and reverse-engineering KS firmware to see what is happening in the "guts" of the beast ... Link to comment Share on other sites More sharing options...
US69 Posted July 21, 2016 Share Posted July 21, 2016 i can say that on riding the KS16 on v1.13 this never happends...so i really think its a firmware bug. ks14...7 months...nothing...not firmware upgradeable Link to comment Share on other sites More sharing options...
Jason McNeil Posted July 21, 2016 Share Posted July 21, 2016 Sorry to hear, I'll investigate & try to get to the bottom of it. I've reached out to Chris (he's got quite a few KS16 Customers) as well as Tina to try to get a better understanding of both the nature & extent of the problem. What I find baffling is that KS have sold over 1500 KS16s, & the v1.19/1.20 firmware is over a month old; being reproducible they must surely have some information about it. Based on the symptoms of the description alone, I'd speculate that maybe there's some sort of current restriction management stuff going on under acceleration (this is not based on any evidence & is only a conjecture). Hope to get some preliminary info when China comes online in around 8hrs... Link to comment Share on other sites More sharing options...
Blunzn Posted July 21, 2016 Share Posted July 21, 2016 6 hours ago, Chriull said: This happened to me on my KS16 about 3 times in total. I weigh around 90kg and i prefer to start driving from standstill. My brother with ~20kg less and making "flying starts" never had this prob... i had it once while starting from a lawn, which was quite even (no pan in the ground) Link to comment Share on other sites More sharing options...
US69 Posted July 21, 2016 Share Posted July 21, 2016 what i found really interesting is, that no One said a word about it... Until the first one went up ;-) never blame your own wheel-beaviour :-) ? Link to comment Share on other sites More sharing options...
1RadWerkstatt Posted July 21, 2016 Share Posted July 21, 2016 please check capacitor connections and firm glue All firmware versions are trouble free! I hope i can help. 1RadWerkstatt Link to comment Share on other sites More sharing options...
US69 Posted July 21, 2016 Share Posted July 21, 2016 i would prefer the term "known as trouble free until now" as alone 5 people reported the exactly same issue.... with only occuring when start from a stand-still, lawn, post...this behave will not so much been seen by "advanced" riders...as they normally start with a push and without holding to something.... Link to comment Share on other sites More sharing options...
1RadWerkstatt Posted July 21, 2016 Share Posted July 21, 2016 i will only say it is not a firmware issue....i will check with KS and Jason Link to comment Share on other sites More sharing options...
US69 Posted July 21, 2016 Share Posted July 21, 2016 here the report i got from another memeber when i have a conversation about KS18 1200 Watt: I have never experienced cutoffs or failures of any kind, only a rare glitch (see my topic on that) when mounting. Try putting your wheel in a ditch of some kind, and try mounting a few times. As you want to go from zero-speed, the wheel is initially not moving. When the power required to start rises with no movement (because you are in the ditch), sometimes the software cannot choose between braking and accellerating, with a failed mount as a result. I wonder if you can duplicate this ... and now add my report of my first try with my new KS18 from up there...started on a fence...also...because of the first try of KS18 ....and i swear i checked if wheel had powered and stabilized! i just tought, damned, NO! but after that first glitch...i never experienced it again.... 20 minutes ago, 1RadWerkstatt said: i will only say it is not a firmware issue....i will check with KS and Jason thanx for trying to help!!! Link to comment Share on other sites More sharing options...
DS Posted July 21, 2016 Share Posted July 21, 2016 14 hours ago, HEC said: I remember one or two forum members here in forums mentioning previously "overpower" warnings with older versions of the FW - maybe this is related? I was the one who reported several times of this "overpower" problem when starting off. I had pretty number of "folds" as you say when with 1.15 FW. The problem lessened with 1.20 but still exists. Sometimes the wheel reports "overpower" and throw me off, sometimes just loose power for half a second and I feel it. Only when I start, in the very beginning of the ride, never after that. The level of battery charge never matters. IMO, not a mechanical issue, since it got improved with FW upgrade, but who knows... Recently, I "invented" remedy After power the wheel and before step on it I shake it with my hands firmly forward and backward 2-3 times and then step on it. So far, so good, but let's see... Link to comment Share on other sites More sharing options...
tinawong Posted July 22, 2016 Share Posted July 22, 2016 To King Song Supporters: I am sorry not to keep track of forum topics about King song frequently and failed to answer kingsong supporters’ questions. Yesterday, I got feedback from our partner Jason about the “cut-off” topic. We take it seriously , we did have got few feedbacks before, it is our mistake to only inform about those emailed us. Here I’d like to list a summary of the issues we got 1) Fall off at the start Some reported to us that they fell off when they start their unicycle. After checking, they start from standstill. We made a change in the firmware for all of our models this year, that is: At the beginning of the first 2 seconds, unicycle will detect itself automatically, if stepping on unicycles right away, giving it a power suddenly, it will have risk to lose balance. So it’s better to: a. After power on, wait for 2 seconds, then start to ride ; or push the wheel back and forth to get some balance. b. Avoid suddenly acceleration at the beginning If this setting is not good, we will find a solution to optimize in firmware. 2) Fall off at high speed The top speed of our 16” is 30km/h, but it relates to battery level. If in low voltage, still keep high speed, there is risk to power off, so if there is an alert from unicycle, pls do be caution and do not accelerate any more. Also, I got feedback from some riders, they run over our top speed, they think it should not cut off , because there is safe speed reserve. Yes, in thoery, it should be. But if accelerate too fast, the temporary speed is hard to control. So for safety, pls don’t try to exceed our safe limit. Tips: To ride safety, pls don’t try to push the wheel forward and backword at the same point for a long time or if you stuck at hole, pls step off immediately rather than keep pressing the wheel. Thanks for all your support in King Song again. If what I mentioned is not correct, welcome to point out. Cheers Tina Link to comment Share on other sites More sharing options...
DS Posted July 22, 2016 Share Posted July 22, 2016 1 hour ago, tinawong said: or push the wheel back and forth to get some balance. That confirms my "remedy" Thank you, Tina for the info. Link to comment Share on other sites More sharing options...
HEC Posted July 22, 2016 Author Share Posted July 22, 2016 2 hours ago, tinawong said: 1) Fall off at the start Some reported to us that they fell off when they start their unicycle. After checking, they start from standstill. We made a change in the firmware for all of our models this year, that is: At the beginning of the first 2 seconds, unicycle will detect itself automatically, if stepping on unicycles right away, giving it a power suddenly, it will have risk to lose balance. So it’s better to: a. After power on, wait for 2 seconds, then start to ride ; or push the wheel back and forth to get some balance. b. Avoid suddenly acceleration at the beginning If this setting is not good, we will find a solution to optimize in firmware. Hello @tinawong and thank you for posting here at forums in regards of this issue. I just would like to point out (as per details in the issue description in first post) that in either of the cases the wheel was switched on for a couple of minutes before riding as it was being pushed (while powered) to take off point and wheel was always tested by pushing front / back by hand a few times that it's balancing. Also the acceleration was very mild and surface flat with no bumps or ditches. So both a. and b. point above are unfortunately not valid / relevant in this case. 2 hours ago, tinawong said: Tips: To ride safety, pls don’t try to push the wheel forward and backword at the same point for a long time or if you stuck at hole, pls step off immediately rather than keep pressing the wheel. Can you please advice what is considered a "long time"? Many riders myself including are "standing" at crossings or traffic lights waiting for green without stepping off the wheel and holding onto the lamp post, traffic sign or fence and indeed that's exactly what happens with the wheel as it will be switching briefly the "driving" direction from front to rear and back again. Depending on the traffic signal intervals this can take up to 2 minutes thought that's fairly rare - usually it could be anything between 15 - 90 seconds in average. Thank you for your support Tina and thanks to both @Jason McNeil and @1RadWerkstatt for participating in search for solution. Link to comment Share on other sites More sharing options...
Jarrett Bowers Posted July 22, 2016 Share Posted July 22, 2016 Has anybody experienced this with the 800 watt motor KS18? I have this wheel and so far have not had this issue but then again I don't have much mileage on it yet. I don't think you can update the firmware on this model so if no one else with this wheel has run into this that should confirm that it is a firmware issue right? Link to comment Share on other sites More sharing options...
US69 Posted July 22, 2016 Share Posted July 22, 2016 on some very new Ks14 you can update the firmware...perhaps on the ks18 800 Watt also? just take a look in the new upp on firmware...if it is not updateable like my Ks14 ..it will notice the Version 0.00! as no one has this on Ks14.., i think then you re out of the game, also Link to comment Share on other sites More sharing options...
Jarrett Bowers Posted July 22, 2016 Share Posted July 22, 2016 @KingSong69 any chance you can post a screen shot of app showing the version #? I can't find it anywhere in my app. Thanks! Link to comment Share on other sites More sharing options...
US69 Posted July 22, 2016 Share Posted July 22, 2016 @Jarrett Bowers you have the old grey App? It's just in the New "Green"! Link to comment Share on other sites More sharing options...
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