In this thread, mostly denial.
@tech.shit you participating the D. I. R. T. games this year? Itâs an offroad skills competition played like Horse in basketball. Iâd love to see your offroad equipment rocking!
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Is it happening again? 
Now that I finally have a board that would actually be perfect for this 
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well played dude 
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I understand that. This is WAAAAYY too much to fit into a backpack.
But what about if I use 2 or 3 99wh battery packs?
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You donât really need thread to grip on shitty terrain. Karts often race on dirt tracks with slick tires, thereâs whole racing seriesâ dedicated to that⌠Iâve also run wide slicks offroad with decent results. A good rubber compound along with a good amount of width makes more difference than thread does in my opinion.
The 5" height sounds serviceable but definitely requires some skill on serious terrain.
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So first letâs get a baseline for a few things,
What kind of wheels are you intending to use for this?
Hub motors - cheap, compact, very efficient, motor is inside the wheel, sucks terribly for comfort, poor reliability in many cases, and itâs effectively impossible to go off-road with hub motors.
90-110mm urethane - less efficient, less compact, more expensive, substantially more comfortable, a little bit of âoff-roadâ can be done if itâs well packed and the rider has a bit of skill.
Sr125 rubber wheels - less efficient, less compact, more expensive, substantially more comfortable, Opens up more off-road capability than urethane wheels.
6-8in pneumatics - even less efficient, even less compact, similar or sometimes lower cost to SR125 wheels, more comfort and can generally handle most off-road other than deep sand/mud/snow.
Iâm also going to provide some efficiency examples Iâm ~180lbs
My backfire zealot uses 105mm urathane wheels and belt drives, that board uses between 19-24wh/mile
My Hummieovan uses about 25-30wh/mile
My McBoardface uses between 28-40wh/mile
But I ride that more aggressively than anything else.
@Pecos Blue Koi uses hub motors, what does blue Koi consume per mile?
(I recall this being very efficient)
IMO you can build an efficient compact, flight safe board or you can build a powerful, fast, off-road capable board, itâd be incredibly difficult to do both.
For a powerful offroad board that might get you halfway to your stated range goal. As already stated, ignoring your portability goals, youâre talking about a 600 Wh pack minimum.
Iâve been looking into building a board I can carry on to a plane, but what I ended up with for my design ideas was about as far from the rest of your requirements as possible. I was going to do a dual hub motor board because that would be the most efficient and compact. I was actually going to try to build a board that didnât even have to fold. The diagonal length that will fit in a carry-on is something like 28", so I was going to do a 28" double hub motor with two 10s1p 18650 packs that could be combined in parallel. For the 100 Wh limit, youâre looking at either 6x21700s, 10x18650s, or using lipos. Lipos might actually be the smartest because youâre less likely to get hassled about them in security, in my opinion, but I was leaning towards 10s 18650s. You could also split a 12s1p 21700 pack into two 6s1p packs. I didnât want to carry more than 2 packs, though. I figured with hub motors I could get maybe 10 miles with 200 Wh, and since the point of my idea was mostly last mile stuff, I thought that was fine for what I wanted.
Anyway, IMO, youâre trying to combine way too many things into one. When you do that, youâre bound to end up with something that costs an enormous amount and isnât very good at anything it was designed to do. If you want a serious offroad board, youâre going to need to check it and carry on a bunch of batteries separately. If you want something you can carry on, youâre going to have to really par down your expectations.
Iirc it is something between 6-10 wh/mile. For reference I would cruise around 15-20mph and weigh 200lbs. Cant find the record rn but ill update if itâs off by much when i get home
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I havenât actually tuned my hub motors well in the past, so maybe they were wasting a lot of energy, but that would mean something like 45 miles on that pack, which seems insanely high to me. Itâs 10s3p p42a, right? Can you actually go about that far on a charge? Maybe I donât need as much battery as I thought if I set things up right.
I think itâs due to using unlimited hub motors specifically, those somehow are ridiculously efficient. On my unlimited hubs (on this build) 12S4P P42A pack on them gives me about 100 km / 60 mi of cruising at around 15 mph (if I am trying to be efficient and not use excess throttle). Good luck finding unlimited hubs though, they arenât sold anymore and you canât even buy sleeves for them.
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Damn that looks cool and fun as hell. If I can make it out with my build in a somewhat respectable state Iâll definitely tear up some ground with yâall.
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Hmm, interesting, my main experience with hub motors has been some really crappy Lingyi ones. I think I also set the motor current too high to the point where full throttle wasnât doing much more than wasting energy, but I never really cared to try to dial it in.
Iâve been trying to figure out the best bet for decent hub motors that I can hopefully buy sleeves for in the future. Iâm leaning toward Meepo since theyâve been around for a bit, but I havenât made up my mind. Iâm pretty sure those are also lingyi, but they at least look better than the ones Iâve used before.
It is absolutely too much battery for the build. Could have easily gotten away with 12s2p and been more than happy with the range. Im getting better at estimating the range a pack will get me but i do kinda tend to go too big with my packs in general. I can live with that.
If you want to go smaller, like dual 99wh packs it might be worth it to look into the new tabless cells. If specs are consistent you can drive them harder and charge them faster for less of a penalty. 12s1p split into two 6s1p packs is just over the 99wh limit and 3 x 4s1p packs are well under the threshold.
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after some googling and re-reading the thread from 2021 I stupidly realized this is online and I donât have to fly anywhere.
hell yeah Iâm donna take some videos of myself eating shit trying to do the same tricks as you guys. sounds like a blast.
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Shouldnât 6s be under the limit for most high-power cells? The limit is actually 100 Wh afaik. That means for 6 cells, itâs 16.67 Wh per cell. At 3.6 V nominal, that is 4.63 Ah. There are cells that are more than that, but most of the high-power ones are under that. Iâve seen factory-made 7s packs that were mislabeled to be okay for planes. They labeled 7s 4000 Ah packs as 100 Wh when technically it is 100.8 Wh.
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That sounds rad. @Venom121212, there should be a running thread for this. I know guys from my group would be interested.
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Good because that shit would get expensive!
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My build has flight safe batteries.
You just have to combine two to use in the board and swap them out with the other two when they run flat.
The wiring harness is pretty straightforward if you understand how BMSâs are wired but they still take up some space. Itâs a compromise I had to make for this board. I currently have three, all DIY.
For such a wide range of requirements, there is no âone size fits allâ for eskates. You either make compromises or have multiple boards for most of your use cases.
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