Motor overkill?

Hello all! I’m debating between two motors - sk3 6364 vs 6374, 190-192 kv. I want to mount a pair of either one on my drop-down deck, which is using trampa infinity spring trucks and 8" tires. I plan use this for cruising/ commuting, with the occasional adventure down a dirt trail. There are a few medium-sized hills in my area, and I’d rather have hill-climbing power and range over speed (within reason). I saw the 6364, then noticed the 6374 and started wondering, aware that there IS such a thing as too much power, too much of a good thing, etc. So, are 2 6364s enough, plenty, or overkill? what about the 6374?

6374 if they will fit would be my choice. I believe the extra power will be a plus with 8" tires.

Good point, I hadn’t thought of that. I imagine that the bigger diameter wheels will also help maintain some of the speed.

Yes but you will use gearing to counter act the large diameter of the wheels.

True. I’m aiming for a decent all-rounder.

The 6374 will give you maximum torque.

It’s a nice motor - but isn’t voltage a more important consideration?

12s 5065 vs 8s 6374 - wouldn’t the baby motor at high voltage be a lot more powerful?

That’s the problem, I’m not sure. I’ve read a lot of people’s builds as having either 6364 or 6374. I know I want higher torque, hence I’m looking at ones with 190-192 kv. As for the battery, I’m getting one locally (Israel) to avoid the massive hassle I know I’ll get with customs. It’s a 36V, 5.8 Ah, Samsung cells, though I can’t tell from the pic or info how many (is there a formula to figure that out?). I figured I could get two and wire them in parallel. Check me on this: it says overload protection is 4.35V-cell / 43.5V-pack. so by that math it should work out: 36/4.35=8.275 ~ eight cells? going by the pic it could as many as 10 or 12.

You could compensate for higher voltage by increasing the amps with the 8s system and get similar total instantaneous power out the system that way but the smaller motor will get hot sooner being smaller and also possibly over-worked. Heat being the limit

I’ll look into that, although I’d like to keep the number of individual packs to a minimum. If it helps I can send the link of the store page, or perhaps just write out the rest of the stats.

6374 will produce more torque than 5065 and with less heat as @Hummie mentioned.

can somebody please explain to me what overkill is?



Haha. I think real motor overkill would be when the motor increases size so much that iron losses are greater than copper. With losses being equal between those would be ideal and the most efficient size.

Still waiting for someone to do a 6s vs 12s on half the duty cycle test if anyone can do an easy experiment that would tell us how efficient higher kv are.

Its quite simple actually. I would go for the 6374, the highest overkill torque. Why? Because the larger the torque, the easier it encouter rough terrain with slight advantage in battery consumption. Riding on normal street is nice and save between 20kmh upto 30kmh. More than that its dangerous for you or anyone around you.

The advantage of larger torque is that its easier to gear it up if one day you want more speed. However gearing down is not as nice and easy to work with.

But hey double 192kv with mtb setup is already overkill.

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Why is it dangerous to ride over 20-30kmh on a 6374?


“Suitability - Just because you can doesn’t mean you should” Welp, guess I’m strapping big ones on there…

This whole 6374 set up got my interest because that is the set up im going for i have dual 6374 motor and im trying to figure out the battery set up next. On whether i should use single 12s4p battery or two 10s4p on the dual motors. So im now wondering why is it dangerous to run the dual 6374?

Meanwhile, right here on the forum: