EMTB 12s6p SK3 149kv Focbox build (ALMOST DONE) VIDEOS

So close to finishing this build. Been working on it for couples months now whenever I have the time too. You can see in my recent post I had a problem with my first enclosure being not tall enough. Eventually got another one that’s taller and everything fits. Here’s the parts

Motor: 149kv Sk3

Gears: 72/16 @Idea

Mounts: @Rithblu

Wheels: 8” MBS

Trucks: Matrix (old style)

Deck: some random amazon deck

Battery: 12s6p 30q Samsung

Esc: Focbox (first time user with focbox been using 4.12 vesc)

Bms: 12s charge only @thisguyhere

Switch: @Martinsp

Further parts adding:

Heatsink for dual focbox from @Rithblu, Bluetooth module and some free binds I think there called.

So the problem lol :joy: Easily fixable I believe, just need to hit the hardware store and get some 12mm speed washer to space out the flywheel away from the mount as there are touching

Another question: I’m use to building boards but not to much of embt. On the vesc tools I was thinking of putting these settings, I know it’ll work for a regular Esk8 but for a emtb will theses settings still be fine. What you guys think

Motor max: 60 Motor min: -60 Batt Max 50 (each focbox is 25a) Batt Min -12 (each focbox is -6a)

Will this do ? Was thinking maybe lowering the Motor Max

Update: Here are some videos I’m the one in the red helmet Purple helmet is my friend Just waiting to receive my crossbars that @Rithblu already sent me so I can install them and post some dope ass photos for y’all before I mark topic as complete. Will be adding @Rithblu dualfocbox heatsink later on, right now I just want to ride and enjoy it for a bit before I add anything more. Thank you to everyone and this forum. Without everyone here I couldn’t have made my 4 builds this year :blush: p.s today’s my birthday to 31 :flushed: lol But you guys are the awesome ones here :sunglasses:


On my 12s6p, my motor max is 60 and batt max 60 per esc.

Test with ur current settings, if it feels stable, crank that shit up.


60a per esc :flushed: that’s your max you can do though right. But once I can get a hold of those space washers I’ll be able to test the current settings I have. I’ll keep post updated

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? how to understand that? It´s what you have and what you plan to set later?

With the focbox and that extra heat sink you can easy run bat max 50a per focbox and bat min at -12a

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Just updated it. After I read it again it did look confusing lol :joy:

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now i get it :wink: but non the less, you can save up the bat amps to 50a and -12a each focbox if you want (you don´t need thoug :sweat_smile:)

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if its not to much of a bother for you switch the motor mounts to the opposite side of the clamps this will give you more room, so it won’t tough the gears, so no need for the spacers.


Freakin genius :scream: Once I get home ima have to try that Right on for the tip I think it just might work. I’ll keep you updated as well

Edit: tried doing what you said but my motor pulley to far on the side. My motor shaft not longer enough where the pulley and flywheel wheel will be lined up

An Oh Yeah, the red counter sink washers are meant to be used on the screws that’s holding the motor.

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Do you have a link to the battery meter?

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12V Lead Acid Battery Capacity… https://www.amazon.com/dp/B0759HB8D4?ref=yo_pop_ma_swf

Edit: fixed my issue with flywheel to close. How do I order those crossbars for your mounts ?

Is this the problem?

It’s for 12V?

Just give me the length you need, the inside to inside of the mounts.

No? It was my flywheel hitting my pulley but I’ll have the issue fixed tonight after work. Have to buy 3 more washer

It still reads my volts correct :thinking: Also I’ll let know the length once I get home

I had one on an 8s setup not sure the voltage max was , I rebuild the board and upgraded the battery to 12s4p it was telling me it was 100% till this day so i put it on a desktop charger and it was really just a little above my cutoff.

@Rithblu Here’s what volt meter says image It was around 49v earlier before I finally fixed my problem :grin::grin::grin::grin::grin::grin: Only rode for about 15min but not to much since it’s dark af right now. This Friday I’ll have more time with the board and hopefully everything’s runs ok. Also didn’t apply locktight lol so have to go back and do that. I wanna make sure everything is running ok before I confirm this topic as COMPLETE. Also here’s the measurement between each mount. Sorry didn’t have mm reader that long hopefully this helps. image

Please check to make sure that your motor is close to center to the mounts as possible, because if your belt is to long the motor will be pulled back to far to use crossbar.

If your able check to see if you can fit 5/16 round crossbar in the mounting hole on the mounts.