New Electric Skateboard

Posted byRandall 315 Comments on New Electric Skateboard

Happy pi day, everyone!

My skateboard was broken for the past five or six months, and rather than get it repaired, I traded it in for a new, more powerful model. For a cost of about $120, I now have a board that can go zero to 20 mph in four seconds. This is a pretty alarming speed and has finally gotten me to buy a helmet, but it also means I’m one step closer to becoming a Kourier. I just need to talk to Neal Stephenson about some engineering issues with those radial-spoke wheels …

For anyone interested in buying a board, I recommend going to eBay and looking for a cheap used one to try the idea out. My first board, a vaguely toy-like e-skateboard ($31 on eBay in 2004) had an 80-watt motor (still surprisingly powerful — it managed to tow four people at one point). I bought a few other cheap used ones, and then, having decided these things were indeed awesome, I decided to spend some more money on a proper board for getting around the city. I got a 250-watt Exkate Raptor 3.0 for $320, which I talked about in an earlier post.

This new board, a Pro Module 600, is also made by Exkate (now Altered Electric Skateboards):

The old 250-watt board was still not quite powerful enough to climb Somerville hills without complaint (I’m at the upper end of the 170-lb weight limit), but this new one has a 600-watt motor, which handles them no problem.

According to Science, 600 watts is about 80% of a horsepower.

This suggests that if you found a smallish horse (say, 75% the strength of a standard one), and started a tug-of-war using this new board, you could actually win.

This is of course dependent on friction and when the board can actually supply maximum power and so on. But let’s pretend it would work.






Edit: Taylor of Exkate posted with some technical info, and I answered some other questions in the comments. He mentions that if you want to order a board, call him (949.951.9500) and mention xkcd for free shipping (which can be significant). Disclaimer: They aren’t paying/giving me anything, they didn’t ask me to write this, etc. If you’re interested but don’t want to spend a lot yet, I recommend trawling eBay for a cheap board to try the idea out.

 

315 replies on “New Electric Skateboard”

  1. Also, you know, the fact that every time someone mentions a specific xkcd comic, I say “Oh, god, that one is one of my favorites!” I realized I was doing that and probably ought to stop, as when ALL the comics are your favorites, it somewhat defeats the purpose of a ranking system… 😦

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  2. Yeah, I think it does, since he was doing both of the experiments. Making out with yourself sounds unusually fun. And weird.

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  3. It seems noone else pointed this out yet, so I have to:
    One HP is the power an average horse can sustain for a whole day (like, when pulling a cart or turning a mill) and is about 735 watts. For a short time, it can do 20 times that without problems (says wikipedia).
    Also, As others have pointed out, in a tug-of-war, only static force counts, not power. And since the batteries will only supply a certain maximal current, you will probably lose agains any horse, pony or miniature. Even if we forget about mass and firction and stuff.

    But if you raced a horse uphill, you’d beat it if the distance is too long (or the hill too steep) for proper gallopping. Reason: The horse is much heavier than you plus the board, so you’d get more speed for the same power output.

    This would of course end entirely different if squirrel-Girl and E-board-Boy teamed up, because there’s a lot of things you can do with 2MW electric power, a laser and an electric skateboard …

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  5. Hmmm… actually, I seriously doubt that you could beat a small-ish horse in a tug-of-war. For one thing, “horse”-power is actually based on the power supplied by a pony, harking back to the days when they were trying to sell the notion of using engines rather than horses to pull railway cars. If you compare your engine to the number of ponies it can equal (ponies being weaker than horses), it sounds more impressive. So really, 80% horsepower would more accurately be described as 80% “ponypower.” And since strength doesn’t scale linearly, you’d have to be competing against a REALLY small-ish pony to get 75% strength. Maybe a Shetland yearling. Which would be kind of cute, I suppose.

    Also, horsepower (ponypower) is an average value of the force that a horse (pony) could supply over an extended time. The time involved in hauling railway cars all day, for instance. But in a tug-of-war, which involves relatively short bursts of energy, that pony would yoink you right off your skateboard and drag you around a bit while his pony friends point and laugh.

    Not to mention that your OWN strength would be the limiting factor in the first place, unless you tied the rope to your skateboard.

    However, all of these considerations are rendered null and void due to the sheer awesomeness of that illustration.

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  6. Ah, oops… I see others have already pointed out what I wrote in my comment. I should look through the comments before posting…

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  7. “This would of course end entirely different if squirrel-Girl and E-board-Boy teamed up, because there’s a lot of things you can do with 2MW electric power, a laser and an electric skateboard …”
    Hmm… what about a Dyson laser and a gravitational wave surfboard…?

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  9. Mad Props on the Snow Crash Reference, dude! YT was amazing, and the first chapter was the best of anything I’ve ever read (mostly because I am a ‘za mercenary myself).

    I might, just might get one of those skateboards. Grand Forks, ND (my stomping grounds) is prime area for one of those – all the flat you could want, truly amazing.

    TRH

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  12. You make me want to get a board to go from the train station to work. It would have to be light weight enough to carry on the train.

    and

    every time I see that comic I have to giggle.

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  13. interesting thought, Cesium. Maybe that’s how the Silver Surfer flies through space.

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  15. sorry dude, i love your comic and your blag and all, but an electric skateboard is one of the stupidest, laziest things i have ever heard of. you need to learn the joys of cycling.

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  16. To the guy who asked if they sell to Australia, I live in Denmark and have a Slash Bat 250 from exkate, and when talking on the phone with them, it sounded as though they weren’t unfamiliar with international orders.

    Some complaints you should watch out for: It is WAY heavier and bulkier than I was expecting when I read the specs. You read 27.5 pounds and think, “that’s not so bad… I can pick that up over short ranges.” Living in Europe, I got it with the idea of going board-train-board or board-bus-board, but its a pain. I do like the idea of locking it up like a bike instead of taking it around with me, so I’ll have to give that some more thought. Also, top speed is freakin scary. Xkcd claims he can ride it stable, but although I’m pretty athletic, I start to get wobbly at about 70%. That’s alright with me, because there’s normally no need to go that fast (I like cruising around on the board as opposed to getting someplace quickly). Finally, I would not at all recommend this for folks who aren’t used to riding boards of some type or pursuing other athletic endeavors. Watching my dad and gilfriend try to awkwardly keep their balance made me pretty nervous.

    xkcd: Have you had any problems with drive wheel wear? Mine is still pretty new, but the clearance between the wheel and drive casing seems awfully small. I feel like I’ll be grinding it up in no time and was wondering if you’ve found this to be the case.

    Despite the fact that it wasn’t exactly what I was anticipating, I have to say it is sheer awesomeness. I’ve made a lot of unexpected new friends, from little screaming arab children to chemical engineering professors. I’m at that point in life where I need something to keep me young, and this is the most fun I’ve had in a long time.

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  17. How do these hold up in the rain? I’m thinking about something like this for commuting (currently ride a motorcycle for that) but it’s only about 4 miles each way…

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  18. I’m looking into getting some sort of electric board, but I’ve got a bit of a strange question.
    I’m only 97.2lbs (I’m 20 years old- weird, eh?), and I’m worried. Would the Exkate boards be TOO fast for me? Would I be able to keep them stable with my meager mass?
    Should I stick to a toy-like board instead? I really don’t want a wired controller. =(

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  19. StaticSignal:

    no, get the exkate board. I weigh about 100 pounds and will get one which supports riders up to 260 pounds because that would allow me to have a passenger with me. (that and for the speed.)

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  20. WOw… a ball pit and a skateboard? I wish I were you… Actually, I don’t. Cause then I’d have to be funny all the time, and that would be too much work.

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  21. Pingback: Skates/board « Angel

  22. To Brad, who posted “Instead of battery-powered, how about putting a flywheel on a (recumbent) bike? If you could somehow get the brakes to regen the flywheel, you could use the flywheel as: 1) stored energy that lets you easily start back up from a stop, and 2) a gyro that keeps the bike from tipping over when stopped. Now that’s Science.”

    Flywheels don’t have to be that heavy, of course, they just have to spin fast, so it wouldn’t have to add more than 2-3 pounds to the bike.
    However, the gyro-effect would start as soon as you started braking, so during the 10-50 meters until the read light, you wouldn’t be able to turn your bike. Or, well, you could, but depending on what axis you mount the flywheel on, you’d get a hell of a precession.
    It’d be great for shows (riding sideways on one wheel, in outwards circles), but for practical applications, I think I’d choose the bike that doesn’t launch me sideways into traffic ^-^

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  23. This is actually how I plan to get around college campuses, as soon as I can get some money to buy one.

    It’s either that, or get one of those Razor scooters that fold so I can stow it during class.

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  24. why don’t we do more of this in physics? theres so much scope for love through science

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  26. XKCD said,

    but it also means I’m one step closer to becoming a Kourier. I just need to talk to Neal Stephenson about some engineering issues with those radial-spoke wheels …

    —

    I can’t believe nobody asked this.. maybe you’ve explained it in another post that I can’t find?

    What are you doing for a magnapoon? I mean, I suppose you could just do something retractable with a big-ass electromagnet on the end… but, I’d like to see what you came up with — especially for one-handedly operating the retraction and magnet on/off… plus, is there anything other than skill keeping you from putting a windshield out?

    Also. out of idle curiosity. Is it legal to ‘poon someone like that? Minor consideration, I know… but I wonder…

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  27. Well, you could just position it low enough that it couldn’t hit glass. It could all be controlled with the remote, and maybe mounted on the front of the board. Just make sure you don’t hit a lamp post or something.

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  29. I’m probably way slow with this, but you misspelled “Traveling Salesman” — only one L in traveling.

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  30. AC Propulsion Guy: No he didn’t. Travelling is acceptable, even though firefox catches it as a misspelled word. Do a web search.

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  31. I didn’t actually take the time to read every single post on here so I’m not sure if someone mentioned this. I’m in China right now and it is the first place I’ve seen electric bikes. They are quite prominent in good weather. They seem to be practical, and affordable, only a few thousand yuan (about 7yuan to one US dollar).
    It seems that in my city everyone who is over 23 and doesn’t have a car has an electric bike. And my city has 8 million people in it.

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  32. “Is it legal to ‘poon someone like that?”

    I’m sure he has some other meaning than the one I’m thinking of, but seriously?

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  33. Instead trying to find a small horse of >80% of a horsepower you could just go with a fully grown horse missing one leg.

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  35. Re: today’s comic, “Important Life Lesson”

    I think a children’s choir singing “Jesus Loves Me” as soon as Jay-Z’s album “American Gangster” ended ranks up there alongside the Power Ranger theme.

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  36. Regarding today’s comic. Pft. The Powers Rangers theme is a thousand times sexier than all of Barry White’s songs put through an all-night shuffle all marathon.

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  37. When she didn’t leave the room after music from Final Fantasy VII started playing, I was optimistic. When she told me she cried when Aeris died, I knew it was something special.

    (When she told me moogles got her hot, I felt it all slip away …)

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  41. I just wanted to say if you ever wanted to go man-o-e-man-o with a minature horse I have a couple if you ever find yourself in Albuquerque, NM.

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  42. Hi.

    About Important Life Lesson

    I once did that and I ended up on the music on Miyazaki movies which it turns out was not bad at all to set the mood; It’s kind of classical.

    I selected very carefully as well and it was some pink floyd because it’s my favorite band… I like Pink floyd so much I couldn’t concentrate on the sex…

    So, a good choice is not necessarily something you really like!!!

    Go Go Power ranges doesn’t fit in any of these categories and it’s just hilarious.

    Nico

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  43. This electric skateboard industry might completely take-over, in which case kids would no longer get “Kick, Push.”

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  44. > What are you doing for a magnapoon?

    I’ve been riding the exkate for years (I have 3 in various states of repair)..
    Last summer I grabbed hold of my roommates pickup.
    I’ve bumper hitched many times with an ordinary board, but this was the first
    (and last) with a powerboard. After exceeding the top speed of about 22 mph,
    I decided to hang on and hitch my fate to the truck…..
    At about 35mph the board kicked out….
    (BTW, 50 pound boards kick out a lot harder than regular skateboards).
    Shouldn’t have been wearing flip-flops, but it was a spur of the moment thing.
    Came down perfectly on the flip-flops, and did a Fred Flintstone bumper hitch until I came to a stop… tore up the battery pack, but,
    hey, nothing lasts forever.

    The exkate X-24 rocks…. accept no substitutes.
    (got to try a Li Ion battery pack up at the factory,
    about 3 mph faster, 15 lbs lighter, double the range,
    but they have not yet decided to market them…
    charging hazard

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  45. XD

    “Cool! I just gave a Helicopter Cancer!”

    This is why I read this comic.

    Also; did today’s comic make anyone else think of “Poisoning Pigeons in the Park”?

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  46. I gotta say, I truly appreciate the attention to detail here. Notice that the horse is sliding, but the skateboard’s wheels are locked (at least, that’s how I read it). With a little technical license, this might wave away the obvious differences in weight, given the standard variation between the coefficients of static and kinetic friction.

    Bravo, xkcd.

    Okay, now I’ll have my coffee, and get a little less smart/more smart (depending on whether what I said makes any sense).

    Cheers,
    –joe.

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  47. This is a fun thread… I have an Exkate 3.0 I bought on Ebay for $250 (cosmetic blemish).

    I ride it almost everyday and have the same experience of getting stopped constantly to answer questions. I have ridden skateboards and snowboards for over 20 years so this is kind of a natural form of transport for me. I agree with the poster above, though that watching newbies try to ride this thing is terrifying.

    I chose the 3.0 because of the weight. I pick it up and carry it when I go into starbux or whatever. The 4.0 was just too heavy. I weigh 170 lbs and the thing goes just fast enough for me. I don’t need to go any faster than that.

    I did hit a curb and had to replace a cracked baseplate and bent kingpin. I also replaced the bushings to a stiffer (blue colored) model which I HIGHLY recommend if you weigh > 150 lbs. They messed up and delayed my order but it got here eventually.

    All in all I am VERY happy with my purchase in that it has paid for itself in gas/parking costs and is A LOT of fun.

    I am investigating converting to 24V 10Ah LiFePO4 batteries (which would cost around $600) to lighten it up and extend the range but I can’t find any record of anyone having done so before. I’m not an electrical engineer so I am reluctant to drop the cash if it won’t work…

    Also wondering if those eglide goodyear tires I’ve seen for sale would work on an exkate.

    In case anyone is bored, I videoed riding the thing around Miami Beach:

    Ara

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  48. @Cirujano

    While I’ve never done the conversion on an electric skateboard, I have a lot of experience working with the technology in high-current R/C applications.

    In my experiences with high current transients, you will want to use a configuration that has some caps in it to buffer the output voltage. You would have a set of cells in series to gain the voltage you need (and caps in series to match that voltage) then combine each of the series ‘packs’ in parallel to reach the desired storage (or budget).

    On the fuel cell powered go-kart I am working on, we are using maxwell boostcaps which are 2700 farads each (yes, farads). at 2.5 volts. It goes without saying these aren’t sold at radioshack.

    In case you did not already know, these cells require specialized charging as well. Don’t use the SLA charger or else you will end up with dead cells (or a out of control wicked fire if using lithium-polymer).

    Now that I’ve seen these skateboards, I want one. I think I’m going to ditch the SLA’s from the get-go and working on a direct-methanol fuel cell/LiFePO4/ultra-cap hybrid.

    Unrelated, with the whole horsepower/horse/squirell, one horsepower is the same as lifting 1 pound, 33,000 feet in one minute. Take from it what you will.

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  49. I find it fascinating that you are worrying about the magnapoon and the cool spokewheels, when there is one even more glaring difference between your plank and YTs.

    Hers wasn’t motorised. The spokewheels would need power, of course, as well as the speedo and the sonic cannon, but she got all her speed from pooning passing fools in cars, after the initial footpush.

    I grieve that I cannot (yet!) share in this electric skateboard craze, since at 135 kg I am well above the max weight.

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  50. ‘Also; did today’s comic make anyone else think of “Poisoning Pigeons in the Park”?’
    Only it’s Poisoning Pigeons in a 60-square-km area of France and Switzerland. And instead of cyanide, it’s peanuts coated in… antimatter?

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