"Uncharted Territory" | $20 Hyline Mtn. board + Earthboard 250mm Trucks + 8"/200mm Wheels | 8s/12s | Dual 12s TB Esc's | Korryh Motor Mounts | Kaly MTB Pulleys | Dual 245kv 6364 | Mad Munkey

[Mobutusan]

As the name implies, this is uncharted territory for me in more ways than one, and I encourage any ideas or advice to help me on this project. This is probably my fourth or fifth board that I’ve built, but my first posted project, and my first foray into the world of mountain boards. Also, I don’t think anyone else has electroskated one of these boards, trucks or wheels before, so I’m expecting to have to do some kind of custom work to get a drivetrain figured out. Shouldn’t be too hard, I don’t think though.

After seeing all these crazy awesome mountain board builds, I really wanted to do one of my own, but the cost of doing a Trampa based build or similar was way out of any budget I could justify at this point. So, a couple days ago, I came across a neighbor kid who was moving and he sold me his very rough looking mountain board for DIRT cheap. Lol. As far as mountain boards go, it looks fairly basic, but I think the trucks and wheels are kind of obscure and I don’t know if any readily available pulley/mount systems will be compatible with this setup. I’ll just be happy if I can do some light duty trail riding with this build at least. I’m not looking to go bombing huge mountains or anything. It will run on 12s Lipos with dual Torqueboards 12 esc’s, and possibly a pair of 245kv 6364 Tacon/SK3 motors, or a pair of Torqueboards 230kv 6355 motors, if they are up to the task. I’ll probably go with Freebord bindings, and I’d like to pair it with the Mad Munkey/GT2B controller, which I still have yet to complete.

I welcome any suggestions for how/where to source wheel pulleys and possibly motor mounts, but I’m hoping that Paris compatible mounts would work with these trucks. At this point, I’m leaving toward dual 9mm belt drive with something like 14/72 gearing which should give me a top speed of around 32mph, which is more than plenty. This is mainly cause I have pulleys and belts, but I’m open to chain drive, if there is good enough reason. I don’t know if the belts will deal with the torque and rocks well enough, but realistically, I’ll still probably ride this on the street or through short grass most of the time.

For reference, here are some dimensions of what I’m working with: -Deck length = 36" -Truck hanger width = 250mm -Overall truck width = 380mm (65mm exposed axle for wheel mounting, per side) -Truck hanger diameter = 18mm minimum, round profile, measured at end of hanger. -Axle diameter = 10mm (9.5mm actually) -Wheel only diameter = 105mm -Wheel mounting width = 56mm (bearing to bearing) -Tire diameter/width = 200mm x 50mm -Inner bearing carrier diameter = 29mm

[Michaelinvegas]

Oh this is gonna be good

[Mobutusan]

It better be good, otherwise it’s gonna suck! And nobody wants that.

[oneafrikan]

** pulls out popcorn **

[Mobutusan]

All broken down in its purest form. Oh, if this board could talk, I wonder what stories it would tell. This thing looks like it has seen some rough days. Got a couple slightly bent axles, and the bushings are totally shot. Someone got all schitzo with spray paint and caution tape at some point, but I’ll clean that all up. Wheels and tires look too be in decent shape though.

Any suggestions on the best way to straighten out these axles? I’m thinking of heating them up a little bit with a torch, where they are bent and trying to muscle them back straight in a vice.

[Mobutusan]

Finally starting to come together. I’m going with some 15mm wide, 15t motor pulleys and 65t wheel pulleys from @kaly, and a custom, experimental dual motor mount with aluminum clamp and 1/4" steel mounting arm from @korryh. The dual mounting option was by special request, so I have the option of using these on a mountain board setup, or with smaller, normal street size pulleys & belts down the line if my plans change. Big props to him for taking my specs making these mounts a reality. In fact, my experiences with @korryh and @kaly have been amazing. They both have very reasonable pricing, super fast shipping, and great communication, not to mention very clean, professional looking parts. Highly recommended.

Now onto the building part. The motor mounts are made to fit caliber’s, so I had to grind 3 flat spots on to my truck hangers which have a round profile. Time will tell how well these mounts stays in place on the modded hangers, but they feel like they are rock solid, so I’m optimistic. If necessary, I may take a page from @dinodave’s build and use some long threaded rod with some nuts to tie the two mounts together using the alternate motor mounting slots available.

I had to drill the wheel pulleys to bolt to my 4 bolt wheels which turned out to be super easy since the bearing carrier of the wheels just happened to fit the pulley’s center hole perfectly. So far, so good. Now, on to some pics (without tire & tube).

[Mobutusan]

Man, this DIY stuff is way too much fun! Finally got the trucks cleaned up and the drive system set up and mounted. I’m amazed at how well all these mismatched parts are fitting together, and how crazy solid these motor mounts feel. ZERO flex from the 1/4" steel mounting arms.

I’m also playing around with making some bindings out of some old snowboard straps, but I’m not exactly sure what the optimal angles or locations are for the binding mounts, so I’m kind of winging it. It’s just partially, loosely bolted right now, but feels good so far.

Now, I just gotta clean up and repaint the wheels, slime the tires, pick and mount an enclosure, and wire up the electronics. Can’t wait to ride this $20 beast!!

[mountainboardlover69]

were did u got the motor mount and pullys

[Ackmaniac]

I love the attitude to build something awesome from stuff you might would throw in the garbage. Did the same with my 12S8P battery by used broken Laptop Cells. And it is capable of output 2400 watts and a range of 70km. If you also have a board with the newest stuff which is on the market then you will never love it as much as you will love this board. Because it has so much personality. If i would be you then i would keep the patina of the deck. Looks very unique and you can’t buy a design that only time can build.

[Mobutusan]

It’s up in post #6, but the mounts are from @korryh. The pulleys are from @kaly, but he also sells mounts for MBS trucks too. Both provide quality parts at very reasonable prices.

[Mobutusan]

Thanks for the support and suggestion. This board really is turning into something special for me. Kind of like restoring an obscure classic car with a new engine, suspension, wheels, etc.

I think I’m with you on keeping the original “finish” of the board, although I did lightly sand it down so the surface is smoother and a little cleaner. The wheels were a different story though. I couldn’t leave them all mismatched and crappy looking, so I did a quick and dirty black respray with plasti dipped red lips. I think she’s turning out to be quite a looker, especially since she started out looking like the equivalent of an old crack whore from the MTB world! Just needs electronics mounted, then I’m rolling…

[Okami]

@Mobutusan

she’s turning out to be quite a looker, especially since she started out looking like the equivalent of an old crack whore from the MTB world!

haha this made me laugh really hard some harsh words for your board’s early stage look

I think the wheels turned out to look really nice… So… have you logged any stats for this board?

Milieage/distance - max speed - turning - weight etc?

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PS - where did you get the bushings for it? It wont probably work for me, as im in Eu, but perhaps some crash course on bushing colors would be great…

[Okami]

@Ackmaniac

with my 12S8P battery by used broken Laptop Cells. And it is capable of output 2400 watts and a range of 70km.

How much mah / Ah you got? 70kms seems crazy… I think with 20ah pack it is possible to get about 30km… but 70km is over the board… unless you got a longboard…

[Maxid]

With 12S8P and at 2.5Ah a cell you get 1283.6*2.5=864Wh. With a Longboard’s typical usage of 10Wh per km that would be 86km - on a EMTB that is reduced due to decreased efficiency with pneumatics so something around 70km could very well be possible. And the Ah alone does not mean anything.

[Okami]

Thanks for clarification, yeah, the wh rating is the one to go after when calculating the range… I was just not entirely sure whenever has someone made an emtb which can go up to 70km… For now it seems that emtbs wh usage might be around 18wh, Ive got around 19-20wh/km and I was not going full speed and only 6s/single motor, a friend of mine who got dual drive, said he has got 22wh/km.

So, if there’'s 864wh / 20wh = ~ 43km And, considering he is using laptop cells, I assume they could be already used and their start capacity is probably around 2.2ah, at relatively low discharge.

So for 2.2ah (best case) * 8 = 17.6 Ah (close to 20ah)

[Ackmaniac]

I have a street board with urethane wheels. Of course i would get less range with all terrain wheels. If i would put the right cells in sleds i could get a 100 km range board. And i think i will do that at the beginning of the next season. A all terrain board uses in average 66 % more energy or your get 40 % less range. So than it would be good for 60 km with all terrain and the right cells. With the current setup i would stress my laptop cells too much i guess,

[Okami]

Ok, thanks for input… Yeah, for longboard this is believable.

I think nowind got something like 40wh consumtion when he was going offroad… just dont remember which board it was…

– @Ackmaniac Still - how much capacity can you use out of that pack? I assume the realistic value for one cell could be around 1.8-2 ah… so about 16ah in total… I’ve also got some laptop li ion cells sitting in the shelf but not enough of them to add them to the main pack.

[Ackmaniac]

With street tyres you could go far. Because even 250 watts output would be enough to go 25 km/h if the battery is low. So even when each battery is already down to 3V under load it still would be 36V in total and 1 Amp on each cell gives still 288 watts output. And when i cruise i use in average around 8,5 wh. When i go harder then 12 wh with my dual. but i am a light guy of only 70 kilos. So i am quite sure i could reach the 100 km with the right cells.

[Okami]

Thanks for all of this info! Was not entirely sure about the wh consumtion for longboard, especially based on speed…

250W seems really low… that’s basically the same power the weakest e-bikes use to propel till about 25-30km/h / 15-20mph

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@Ackmaniac I think you could contribute to the inboard battery discussion… they are using something like LG He4 in 12S 1P config… and claim 7-10miles range and up 24mph speed… Personally, I think these ratings should be lowered about, so about 6miles range and around 20mph speed…

Sorry for the offtopic but this is a matter ive thought about recently…

[Mobutusan]

Quick update. Build is almost completely done, and my first 2 mile test run was a success! Here’s how it will look when it’s all done. (With the next stage of batteries/esc’s to come.)