Batbike | 20s7P P42 | Siacosys QS138 swingarm kit | Voltol EM-150 | Mototec Pro 1000W frame/fork

Been keeping this build a bit under wraps until some positive results…If this doesn’t burn me out on ebikes I don’t know what will. I still need to resume my earthwing build. :rofl:

There is nothing smart or practical about this build, but here I am.

Mototec edirtbike
Voltol EM 150
QS138 3000w rated (3x bigger than the my1020 from the razor tho)


What kind of power will 300 w make? What distance do you expect?

The 3000 is just the rating for the motor. The controller will output around 10kw consistently, which is around a 100cc motor/10hp. Nothing crazy but the torque curve on electrics is fun. Distance I expect similar to the razor and very dependent on how you ride. 30km/h probably 50+km, all 90km/h you’ll get like 20 idk. There’s math that can be done to figure it out exactly, I just build as big as I can reasonably fit and haven’t had range issues for my purposes. (sub-50km rides) hopefully my other 20s6p will fit into this one too so I don’t have to build another pack.


Got some progress done. The idea was to put a 120/70-12 on the front rim but there is no hope to fit it on that rim nevermind that the front fork max dimension is 112mm for a tire. I couldn’t find a 90/x-12 anything tire so I got a 100/90-12 hoping it will fit. Fortunately the 120 can still go on the rear and it might be better than the 140 on there now.


Pretty much have a place for everything, front tire should be here in a couple days and still waiting on a 235mm axle bolt for the swingarm. Razor battery fits, I probably won’t bother making another pack for this. I don’t think I would gain a lot other than some convenience.


Again? another one ?!? :joy: man I think you’re addicted. this thing looks like some sort of chopper

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I’m super happy with it and yes this whole time shaking my head that I’ve gone too far wtf I’m doing with my money etc. I think the clc city slicker uses the same backend/swingarm. I took it for a 40km ride today and it’s insane. I’m definitely hitting the bms limit but it’s still hard not to wheelie it full throttle even leaning into it from a start. I think after the bms keeps it at about 100a so it doesn’t hit as hard after. Will be investigating the power issues, also only ran 12 gauge wires to the controller. It hits 90kmh in a couple seconds it’s ridiculous. I still need to set up up gear 3 (another button) on this and have a look at firmware. I went too far here, absolutely insane build puts the razor to shame. We kind of started calling it the batbike :smiling_imp:

I don’t know if the slicker can be had at this price or is cheaper/more but it can be licensed legally as a motorcycle so thats a pretty big plus for the slicker and the economies and of scale, that’s about where it ends for me. The batbike is so much cooler in every way. I definitely paid dearly for the mototec dirtbike, for essentially using a frame and front fork. But that’s what happens when you are shopping at 2am getting highdeas. At least it worked it out in some ridiculous way, the swingarm kit was almost made for this aside from what I’d call minor cutting without affecting structure. (Right peg had to go, swing arm tube needed to be shortened .5cm and 1 side had extra sticking out)

Here’s the budget, which doesn’t include a battery so really not fair to compare it to the slicker that way. Add $900 for the 20s6p in there idk.


Highdea😂 it’s always those that we have to do. But aye 3-4 k isn’t that much when we compare it to a dirt bike brand new. You should add some mirror on at least one side if you legally make it a motorcycle.

Did you include the cost of shipping in the price?

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For the slicker I’m not sure. I’m guessing it would be more expensive. Pretty sure I listed everything in canadian dollars too. I do feel like you can buy something more reliable/complete package for less but won’t be as powerful.

I added mirrors to the razor, I was thinking of just leaving this one simple. Maybe 1 small circle mirror.

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Quality wouldn’t really be there for 4k CAD but 4k USD maybe except for the battery you never really know about the quality until you take it appart.

Good thing if you have at least a mirror that way if the popo stops you and you don’t stop they gonna think you’re running away lmao

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I kind of started with that on the razor but I find the mirrors look dumb. I might add a small circular one lol. Gotta say this build is soooo satisfying, like 2x more satisfying than the razor at least. The power is so smooth and the suspension works so much better. Range doesn’t seem like its affected to badly yet.

Tire came in…100mm wide fits barely. Im so relieved it’s a good fit, there’s literally no other tire that would fit, no 90mm wide 12" street, only 100m wide options. Basically done assembly now and just cleanup. I want to take off the swingarm and clean up my mods lol.


damn that fitment is thighhttttt. I’ve only noticed now but you don’t have hydraulic brakes? I don’t know why but I feel like if you bottom out the front fork your wheel is going to hit the motor controller

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It’s close but I think it clears it. I had to remove the front fender though since that was hitting the controller, now I’m getting gravel in the face. The front only has a cable brake now which I’ve been thinking of upgrading, but the rear is a motorcycle hydraulic that uses dot4. Idk if that will fit the front so I’m thinking a emtb mineral hydraulic for it.

I took it for a spin on a gear 2 and rode about 2km straight at 97kmh sustained. Bike wasn’t hot anywhere when I got home


That’s pretty fast I hope you have proper equipment in case you crash. Merugas has some ebrakes alot of people use them on surrons and such so prob have your disk size too

I had some hownhill gloves on with no pucks, impact knee pads, bum saver shorts and my full face helmet. Not ideal obviously.

I wonder if the clc city slicker uses the 135 motor or a downgraded version in that swingarm. If it’s downgraded then that’s a pretty significant difference. It’s funny though I would expect the opposite, lower quality from the battery especially if it’s designed for lower power output but probably better than random cells from aliexpress :joy:

Here is where I had to cut the swingarm tube 0.5cm shorter. I had to take it apart again since it wasn’t perfect and had some squeaking so regreased and trued this cut off section as straight as possible. The belt is really finnicky to get centered tension and have it quiet but once it’s there it’s so good.

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tbh I’d change the belt for a chain, be scared it’s gonna snap on you some day while riding.

the city slicker is for sure using a lower quality battery and maybe lower quality cells too who knows

squeaking noises for the win lmao

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Idk, the belt looks like some timing belt, if it’s any good it should last a while. If this does snap under 5000km I might look into doing a chain instead, but that does involve some custom machining. Chains stretch and snap too, there would probably have to be a tensioner and it would be noisier. The razor is already a chain drive so it’s nice to have the belt as a different setup. So much extra work :joy:

The squeaking noises are gone fwiw lol. The belt is still travelling slightly and buzzing on some pulls/deceleration but for the most part just electric motor and tire noise.

Side panels hide the mess pretty good. Now just tie wraps need some work and maybe some sleeving.

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yeah the belts are made usually for some cars instead of having a chain timing. You could probably look for a ‘automatic’ belt tensionner just a tensionner with a spring but installing it would be a problem for sure.

side panels do make it look better just need some cable management and it’ll be perfect

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Added a wood shim for the front fender. Now I don’t wan’t to take it off to paint it. Also rewired and recabled the bike, changed the front brake to a mineral hydraulic from the razor. 231km on it already. The factory calibration seems ok, 57kmh was reading as 53 I think, I still need to double check the speed. Would be weird but also not surprising a kit isn’t set up for what it comes with. I had to repin nearly everything for it to work.

Also got the tension basically perfect, it stays centered, just some slight buzzing when letting go of the throttle.


I ended up building a P42A 20S7P for this thing with the bms bypassed. The pack is triple wired with 12 gauge xt-90s, the 2 halves are jumped at the bottom with 2 8 gauge pieces which haven’t gotten warm despite the engine and controller. Also did the mid-tier crimps and triple wired the controller. Width wise the battery barely fit. None of the wires get warm which is an improvement from before, the pull is drastic. I’ll try and get a good acceleration stat, whenever I’ve been riding it just been busy crapping my pants.