Pingouin Posted February 10, 2018 Share Posted February 10, 2018 Hi guys, I have to give you a warning about the Rockwheel GT16v2 (the last generation with the new tire and flat pedals). My friend just had a cut off today, without any warning the GT16 stoped working and he fell on the ground, he was riding on a flat surface at 44kph. Fortunately neither he or someone else was badly injured. We are investigating the cause of this, is it a malfunction ? Are all the GT16 concerned ? For the safety of all you GT16 riders, I recommend you keep it "slow" (under 30kph) until I get further info from Rockwheel about this issue. UPDATE : The GT16 has no "80% power beeping" like on gotway, you MUST keep it slow when the voltage goes down ! Here is some pics of the GT16 after the crash : Link to comment Share on other sites More sharing options...
US69 Posted February 10, 2018 Share Posted February 10, 2018 When i remember it correctly, the official advise from Rockwheel is, speeds over 40kmh are only doable/safe when the battery is over 80%..... @Scatcat Wasn’t there a table of the recommended speeds? Especialy for the v2? Link to comment Share on other sites More sharing options...
meepmeepmayer Posted February 10, 2018 Share Posted February 10, 2018 44km/h sounds like he was just going too fast? Isn't the GT16 officially around 40 km/h max speed? But if that's the case, there should still have been a warning. The guy is not injured? Link to comment Share on other sites More sharing options...
Pingouin Posted February 10, 2018 Author Share Posted February 10, 2018 @KingSong69 Yes I know there is a table with the recommended speed, it's even 35kph, but Gotway recommends 25kph max, if there was a warning before the cut off I would say it's the riders fault, but the fact that there weren't any audible warning or tilt back is what concerns me (I wasn't with him when he crashed). @meepmeepmayer The official max speed is 55kph, and the GT16 has proven capable of approaching these speeds. The guy only sustained minor injuries. With gotway there is the continous beeping when reaching 80% power, with Rockwheel it's supposed to be alarm + tilt back. Link to comment Share on other sites More sharing options...
meepmeepmayer Posted February 10, 2018 Share Posted February 10, 2018 49 minutes ago, Pingouin said: The official max speed is 55kph Really? Isn't this just some kind of lift off speed or so? I'm always cringing when people (especially light riders) approach the lift off speed like it's totally safe under load instead of right at the brink of doom - scary I can only remember the GT16 was advertised with something like 38 or 40 (or 45?) km/h max. Maybe I'm wrong. Link to comment Share on other sites More sharing options...
houseofjob Posted February 10, 2018 Share Posted February 10, 2018 I'm about to do a writeup post on my now deceased GT16v1, shutoff (not cutout - unit fully powered off and no longer turns on) + axle breakage (I baby all my wheels mind you, no jumping,etc...), but when working, my v1 was able set beeps/tiltback at 45kph and regularly travel upwards of 40+kph (also believe the v1, at least, had been advertised to do these max speeds, not lift test, and I wouldn't have bought it otherwise if the speed caps were lower). What I could assess, upon opening, was that the overall v1 wiring was paper thin, and several power-related wires (to the board, charge port(s)) had started to melt and fuse together, so I am led to believe this caused a short. My shutoff happened back last fall (moderate climate), where I had heard a rubbing/creaking type noise after a short lunch run in stop-and-go traffic at top speeds, which caused me to slow down. My GT16v1 eventually gave out, full power off, while riding at walking pace (thank God!). I'm curious to see what the internals of @Pingouin's friend's GT16v2 look like in comparison. Link to comment Share on other sites More sharing options...
s.m. Posted February 11, 2018 Share Posted February 11, 2018 I can confirm two cut-offs on my GT16 v2, too. Both happened at around 35-40kph and both times I was accelerating downhills without reaching any beep while my setting was at 43, 44 and 45kph. First time it happened after ride of around 25-30km so I thought it could be a low battery thing - But the second time happened after a ride of 7km and the battery was nearly full. Before those "events" I was often driving on 44-45kph with a safe feeling on streets and in the wood. Now I wait for the 92V version and my speed alarm is set to 42kph and I don't do agressive acceleration from 25 to 40 kph anymore when I went down a hill. Link to comment Share on other sites More sharing options...
Hunka Hunka Burning Love Posted February 13, 2018 Share Posted February 13, 2018 It's always mind-boggling why manufacturers skimp on wire thickness and quality. It can't be that much more expensive to use a thicker, more durable wire, can it? Maybe it's just a case of someone thinking a certain wire should be good enough without having the engineering knowledge and experience to be certain that it is. I think the quick jump from fun, toy-like 12 kph EUCs that don't see high currents to 44 kph+ wheel rockets over a short development span of time has resulted in finding out about these failures the hard way. Hindsight is always 20-20 of course, and unfortunately the development through failure model of doing things can result in lingering damage to a manufacturer's reputation in the long run. WIth airplanes, helicoptors, parachutes, condoms, nuclear power plants, and one wheeled vehicles, every design component needs to be well thought out and planned for to avoid primary catastrophic failure. I think it's wise for certain Chinese companies to work on implementing a "Do It Right the First Time, or Do It Over Again and Again and Again..." work and engineering ethic. Pinching pennies can end up being quite costly in the for all parties involved. Link to comment Share on other sites More sharing options...
Marty Backe Posted February 13, 2018 Share Posted February 13, 2018 On 2/11/2018 at 3:42 PM, s.m. said: I can confirm two cut-offs on my GT16 v2, too. Both happened at around 35-40kph and both times I was accelerating downhills without reaching any beep while my setting was at 43, 44 and 45kph. First time it happened after ride of around 25-30km so I thought it could be a low battery thing - But the second time happened after a ride of 7km and the battery was nearly full. Before those "events" I was often driving on 44-45kph with a safe feeling on streets and in the wood. Now I wait for the 92V version and my speed alarm is set to 42kph and I don't do agressive acceleration from 25 to 40 kph anymore when I went down a hill. I think it's best not to do aggressive acceleration in general, if the objective is to remain vertical. Link to comment Share on other sites More sharing options...
Pingouin Posted February 18, 2018 Author Share Posted February 18, 2018 Hi guys, So I got some update on the reason for this "failure", it is combination of high speed riding & medium battery percentage, and I have learned something VERY IMPORTANT : there is NO 80% power SAFETY ! So you GT16 riders MUST correctly set your alarms & tilt back, I highly suggest (if you are 75kg max) that you keep it under 40kph, and under 50% battery to keep it under 35kph, I am very sad that there is no progressive warning like on gotway, kingsong, inmotion.... Keep it safe !!!! Link to comment Share on other sites More sharing options...
meepmeepmayer Posted February 18, 2018 Share Posted February 18, 2018 Even Gotway manage to do this better! Link to comment Share on other sites More sharing options...
novazeus Posted February 19, 2018 Share Posted February 19, 2018 i don’t have this wheel and relatively new to wheels but i need clarification. people were saying to charge to 80% to extend ur battery life, which sounds great but if it’s gonna make the wheel crap out, fuggettaboutit. like charging ur phone to 80% like u weren’t gonna get a new one when the battery was toast. unless i hear a good reason not to, i’m gonna keep my wheels between 80 and 100%. Link to comment Share on other sites More sharing options...
Meng Yang Posted February 19, 2018 Share Posted February 19, 2018 I keep my V8's battery level between 80% to 100% whenever possible. There's already not enough power. Top speed and acceleration drops with dropping battery level. I feel safer keeping battery level high. Battery longevity may be slightly affected, but my safety and desired performance comes first. I didn't buy a wheel so I can go slow (or fall). There's more power in my Tesla, so I'm willing to drop battery level to about 50% before charging back to 100%. Link to comment Share on other sites More sharing options...
Mrd777 Posted February 19, 2018 Share Posted February 19, 2018 Let’s not set any fear or lack of faith in this wheel as it’s truly a wonderful machine. I feel very safe on it and it’s the most agile wheel I own. It’s low center of gravity and compactness makes it a lovely quick wheel. Once I’m below 40% it’s obvious I don’t have full power, and use common sense. Link to comment Share on other sites More sharing options...
meepmeepmayer Posted February 19, 2018 Share Posted February 19, 2018 1 hour ago, novazeus said: i don’t have this wheel and relatively new to wheels but i need clarification. people were saying to charge to 80% to extend ur battery life, which sounds great but if it’s gonna make the wheel crap out, fuggettaboutit. like charging ur phone to 80% like u weren’t gonna get a new one when the battery was toast. unless i hear a good reason not to, i’m gonna keep my wheels between 80 and 100%. This problem has nothing to do charging batteries. 80% warning means, the wheel beeps at you when it's at 80% of what it can do (usually motor power I think). Basically, it's telling you "I can't do much more, slow down" (you still need some margin because a small bump can easily get you from 80% to over 100% and that would mean an overlean crash). As this showed, the GT16 crazily enough does not have such a warning, only speed beeps. Because the guy was going fast at low-ish battery, it cut out (not enough power draw from the batteries available) before getting to beep speed. Hence the sudden overlean crash. Other wheels have 80% warnings and may also restrict speed beeps depending on the charge state/available battery voltage (KingSongs). -- What can also happen, is that small batteries (1P or 2P, number of parallel configurations of 67.2V/84V cell blocks) can more easily be overpowered and can't produce enough current in a high demand situation. E.g. some people had cut outs when accelerating a V8 or V5F (I forgot which, but they are both 2P) into an incline, even at relatively full battery. But with bigger batteries (4P like the 840Wh on the 16S, or bigger) that's not a problem, even when the batteries are at a lower charge state. No need to worry, just listen to all beeps and everything will work. Link to comment Share on other sites More sharing options...
novazeus Posted February 19, 2018 Share Posted February 19, 2018 4 minutes ago, meepmeepmayer said: This problem has nothing to do charging batteries. 80% warning means, the wheel beeps at you when it's at 80% of what it can do (usually motor power I think). Basically, it's telling you "I can't do much more, slow down" (you still need some margin because a small bump can easily get you from 80% to over 100% and that would mean an overlean crash). As this showed, the GT16 crazily enough does not have such a warning, only speed beeps. Because the guy was going fast at low-ish battery, it cut out (not enough power draw from the batteries available) before getting to beep speed. Hence the sudden overlean crash. Other wheels have 80% warnings and may also restrict speed beeps depending on the charge state/available battery voltage (KingSongs). -- What can also happen, is that small batteries (1P or 2P) can more easily be overpowered and can't produce enough current in a high demand situation. E.g. some people had cut outs when accelerating a V8 (2P) into an incline. But with bigger batteries (4P like the 840Wh on the 16S, or bigger) that's not a problem, even when the batteries are at a lower charge state. No need to worry, just listen to all beeps and everything will work. at the ranch i use a ton of rechargeable stuff. when the batteries stay good i love this stuff. when the batteries crap out, not so much. segway sends out an alert “charge after every use” others say charge to 80%. dji says store at 50%. i wish manufacturers of wheels would give advice on the best way to keep their particular batteries in their best shape. my terrain is definitely gonna eat up the batteries, just like it ate the muscles in our little legs trying to bicycle in this dirt. we had to learn how to ride on “suicide hill”, kinda the same approach with the wheel. Link to comment Share on other sites More sharing options...
houseofjob Posted February 19, 2018 Share Posted February 19, 2018 Might be remembering this wrong, but didn't the GT16v2 fixes claim to implement 80% beeps? @Pingouin @Mrd777 @Scatcat Link to comment Share on other sites More sharing options...
Mrd777 Posted February 19, 2018 Share Posted February 19, 2018 3 minutes ago, houseofjob said: Might be remembering this wrong, but didn't the GT16v2 fixes claim to implement 80% beeps? @Pingouin @Mrd777 @Scatcat Actually I think it did, I’ll try test it this week to confirm. Link to comment Share on other sites More sharing options...
houseofjob Posted February 19, 2018 Share Posted February 19, 2018 @Mrd777 well, be careful when doing so, it's not That important to test I think, just trying to recall what the official line from the Rockwheel v2 marketing points were.... Link to comment Share on other sites More sharing options...
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