4WD Hub Motor Mountainboard planing

I know this is going to be a very experimental build but i hope to get some tips / thoughts from you before i hit the trigger on my components.

Its my first mountainboard (i have experience with 2 street boards) and my goal is to get a lot of ground clearance. I like to chase my Friend on his mountainboard with my e bike and he constantly hits rocks, roots and branches in rough offroad environments and damages his motor mounts. I hate messing around with motor mounts and hitting them on things so i want to avoid Frustration and go with Hub motors.

first the “regular” components:

  • Trampa 15 ply deck + bindings
  • 12s6p 30Q pack in a hardcase box
  • 4 x Flipsky 4.20 or 4.12 (not sure whats the big difference)

now the interesting stuff:

  • there are mountainboard style trucks that have hub motor mounting options on ali express HERE
    i did not find any alternatives so i will have to make them work. (maybe stronger springs ?)

  • Hub motors are a different story. There a lot of different 6-10 inch hub motors out there with varying weights and performances. The big problem with most hub motors is that there weight to performance ratio is somewhat low so weight will be one of the deciding factors. There are 1000W+ hub motors but they weigh over 5 kg and 20kg+ only for hub motors is way to much i think.

The best compromise i found so far is THIS 10" motor. The problem is that there are several sellers that all claim different stats. Im not sure if there are really different versions but THIS shop lets you select options (but does not change the price ???)
HERE they say the weight is 2,7kg. Thats still heavy but hopefully manageable.

@Martin has done a similar build with maybe the same motors but in his offroad videos it always looks like he drives slow not really pushing the limits of his board.

I also thought about sourcing Backfire Ranger X2 motors since they claim to be a lot more powerful compared to the china hub motors but have not found any way to get them.

what do you think is the maximum acceptable weight for a Trampa style board?

do you know other alternative motors / trucks i could use?

any input is appreciated!

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I love my Ranger X2. The motors seem decently powerful for their weight, even on the hobbywing ESC. You can buy the motors direct from Backfire, or off of ali. This is not exactly what you are looking for, but it might put you on the right path:

I was actually thinking the other day of modifying some matrix II’s and mouting 4 of these motors on it. I was thinking for a carver though, not a true mountian board. Im not sure if these would have the torque or the grip.

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great link i always try to avoid Alibaba since you often need to buy at least 10 or so but this looks promising. Are those the X1 motors? I want some with changeable tires.

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Does your friend had the motor mounts outwards (tail) or inwards?
Since I removed the bottom enclosure and moved stuff up I had no more problems.

he has the older Trampa belt drive with the battery mounted in a top box.

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No clue :man_shrugging: They are listed with the hollow spoked front wheels rather than the solid ones on the X1, but I dont know about the motors. Im actually not certain there is a difference between the X1 and the X2 motors.

That will look awesome

Some things for you to keep in mind, motors usually follow the square relation for diameter and linear for torque, since you don’t have any gearing you need a way bigger motor to produce the same torque without turning it into a heater

Since you are going 4WD you can get “worse” motors and will be fine, that being said, depending or your expectations, even with 4WD it may be a bit disappointing with the comercial options

Just as an example, if you had a board with 8" tires, 6355 motors and 14/80 gearing, for you to have the same performance in a HUB, the motor would have to be roughly a 12085 (120 diamater, 85mm long), I don’t know if any the hubs come close to this, but again 4WD help here

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I found some data on the hub motors

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@Blise518B check out the matrix clamps in this thread

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how did this go?

@cpl-america I tested another Mountainboard and came across some small jumps on the way. I really sucked at jumping but it was very fun. After this ride I realized my board needs to be somewhat light so I can jump with it. When one hub weights nearly 5kg the Board would be almost 20kg motors alone with everything else 25-30kg. That’s almost twice the weight of a more traditional 2WD gear drive board.

So I scraped the idea and went with a standard 2WD setup with Etoxx Mini gear drives and 6374 Maytech motors. All in all I’m happy with this setup and it was definitely the right choise to go lighter. On some steep hill climbs 4wd may be better but in general This setup works very good for me.

The only thing I would change is to go with a Chain drive instead of a Gear drive because there are less annoying things that could go wrong.

We build 2 mostly identical boards with this setup.

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Kinda interesting. I think they might be using the same truck as this:

those are pretty much the only trucks i found that work with hubs without modification. The big problem i see with them is that they only have a spring to turn not an additional Damper inside the spring like the trampa trucks. Im not sure if you can fit one afterwards. If not it will be very unstable compared to other MTB trucks.
I dont see any dampers in the picture. So the ride is probable going to be very wobbly.

The Board they sell is super overpriced anyway. The trucks and hubs are cheap (assuming its the Ali express stuff) and the rest is nothing Special ether. You can DIY a better version for half the money.

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Hi Friend,

This is Maritn. :smiley:
It seems that the 4wd mountainboard is heavy.
But I also hate heavy things a lot.
So I have two new plans.
The first is to apply the Backfireboard X1 motor. I have bought 4 now.
The 4wd configuration will not reduce the weight dramatically.
Second, I would like to apply X1 motor to the rear side and a belt drive to the front side.
I expect this method to reduce weight a lot though.

I can’t descript on the two plans yet, but i will share matiral

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You can fit dampers in them, but I like them more without any dampers. They are not too wobbley but also the quality is not the best.

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Hey, normaly a 2wd belt drive has enough power for most things. Ideally a 2wd hub motor board would be enough but the problem is that hub motors have less power so you need a 4wd hub motor board to get comparable power to a 2wd belt drive board.

My goal was to eliminate motor mounts that bump into obstacles not necessarily 4wd. Sadly i did not find hub motors that are powerful enough on 2wd that are not gigantic.

using a combination of belt drive and hub is not really a solution for me because then you have motor mounts again. If you have 2 belt drives and 2 hubs you might as well use 4 belt drives.

I was also interested in backfire X1 hubs since they are lighter but since you cant replace the tire its not that optimal for a frequent rider. on the X2 hubs you can replace the tire but i did not find a way i can buy them.

my current board weighs between 16kg and 17kg and i don’t want significantly more weight.

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Did you ask Backfire if they sell you 4 X2/X3 hub motors?

i asked in the help chat but they said they dont sell them.

Hi Friend,

I have tried various hub motors for application on skateboard for air tyres.
I found a 5.5inch hub motor for kick board to be optimal for flat riding.
My weight is about 77kg. Ideal for flat riding.

However, I am making a separate board for the offroad.
On offroad, 4WD is more effective(each normal torque) than strong torque 2WD.

So I tried to mix the belt method and the HUB method to implement a lightweight 4WD.
I also hate the belt method.
So, first of all, I am going to try 4WD as a hub motor for X1 first.

And X1 motor is possible to change tire.
Please refer to pictures.


I tested the 2WD driving last weekend.
The tire size is 8.5 inchs and 10 inches.
On-road and off-road tires were changed and tested.
To mount a this tires on the X1 motor, additional wheel hubs are required.
If the X1 motor is installed with a 8.5-inch on-road tire, it will be possible to ride flat.

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Off-road tires is 10 inches.
On-road tires is 8.5 inches.