Popular Post meepmeepmayer Posted May 16, 2018 Popular Post Share Posted May 16, 2018 (edited) (Sry this is offtopic.) 3 hours ago, Ipsiain said: Please tell me more about this. Was this on your acm? What model was it? If i’m going uphill for any period of time i’ll have a peek at the temperature read out in the app hoping to avoid such a thing as melting cables It was on my 84V ACM which was among the first 84V GW wheels (white side panels). In lightheadedness after another really nice and successful cool-hot spring night mountain ride, I went to the pretty steep mountain that was always in my mind for what I envisioned using a EUC for when buying it. TLDR, after pushing the wheel up uninteruptedly on a 10-15% incline gravel road for maybe 7 or 8 minutes, the cables from the motor melted through their insulation and shorted together. This was a a time when Gotway had the problem with the melting/failing motor connectors under high stress, and after the crash I fully expected this to be the issue. In fact, I kind of did the mountain ride in desperation/hope (together with not thinking to much) to find out how the connector issue affected me because mountains is what I always wanted to ultimately do with the wheel. But it was failing motor cabling. GW did slightly increase the cable thickness in further motors (used in the ACM, msuper V3) so newer wheels (motors) of this type have slightly better cables. And I believe (not sure) with the Tesla motor (used in the Tesla, ACM2, ms3 Tesla upgrade, probably the msuper X unless they built a new motor for that), the cabling is even thicker. But the problem remains that the motor cables are probably too thin in the sense that you CAN melt them if you push your wheel up really steep inclines for longer times. The mosfets don't necessarily always fail first, and the temperature sensor creating the overheat warning is on the board, so it won't see overheating cables. We don't have much data as people don't just push their current wheels up crazy inclines to see what happens, but my guess is that wheels probably still are not at a point where you can always expect an overheat warning before anything fails. The dream of "the rest of the hardware will handle anything the batteries can throw at them" isn't 100% true, I think. It's a very fringe issue, though, this happened to me, Marty, as well as some Chinese riders doing mountain stress testing but not many other instances are known despite quite some people doing mountain rides. And perhaps, current wheels ARE better and this wouldn't be a problem. Just something to have on your mind and not crazily overdo it with stressing your wheel. Here's the thread about it, it is a bit outdated and was written in the frustration of the moment, is long and contains a lot of updated/corrected information, and it also links to Marty's thread which is a bit newer. Don't read too much into it other than that you can't 100% expect wheels to "work or warn" (which from a safety standpoint really is what you want in any situation) and it's not always only the mosfets that you have to care about. There's also this where the motor connectors got really hot (but this did not lead to a failure, in fact I never repaired that). But this is NO reason to not buy a (current) Gotway and in principle applies to every wheel. More like general physics: thin cables (high resistance) + very high current + no heatsink for this heat to go = hot. According to @Jason McNeil, the EUC motors themselves would also overheat if driven at their stated nominal for prolonged times (which defeats what "nominal" means), so the entire "very high continuous power for a long time" issue is still kind of unknown, and the motor cables are part of this thematic complex. (Also I'm no expert, this is only what I think) Don't worry too much about this, it's just something that happened. Use common sense in stressing your wheel - any brand, any model. Just like general riding, electronics failure is just something that can happen. Edited May 16, 2018 by meepmeepmayer 2 3 Quote Link to comment Share on other sites More sharing options...
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