A motor question before I pull the trigger

Hi guys,

I’ve had massive help from the community so far and I just need a pointer with this since there are more contradictions the more I read.

Context: 95kg (get down to 75kg twice a year for fight weight), no steep hills, looking to commute for ~ 10 miles a day.

Parts: Motor = (Sk3 6364 190kv) (https://hobbyking.com/en_us/turnigy-aerodrive-sk3-6364-190kv-brushless-outrunner-motor.html1) Pulley System = (12mm Enertion) (http://www.enertionboards.com/electric-skateboard-parts/12mm-wide-drive-pulley-kit/1) Battery = (3x 30C 5Ah 3s in series) (https://hobbyking.com/en_us/turnigy-5000mah-3s-30c-lipo-pack.html1) VESC = (DIY electric skateboards.com)(https://www.electric-skateboard.builders/t/sale-uk-vesc-motors-mounts-wheels-enclosure-gt2b-wheel-pulley-kits/21191)


  1. Higher KV motors provide higher speed on the eSK8 calculator and there was a thread by @chaka back in May 2016 claiming that the ideal KV for my 9s (33.3V) battery setup is ~ 257k according to the formula of 8570rpm/33.3V (voltage of batteries according to Hobbyking specs).

I’m looking to change the motor and get a SK3 6374 192KV according to advice I’ve received so far but wonder if I should opt for KV 6364 245KV according to Chaka’s post so that I hit closer to that ideal range and have a higher top speed.

  1. Will I have enough torque with the 6364 245KV?
  2. If I don’t have enough torque, can I get away with giving the board a push-start?



I am also new to this, but SK3 6374 192KV should be about right torque and speedwise.

But why? there are a fair amount of people, most of whom are very experienced based on their contributions to this forum and builds, who provide conflicting figures. The only one that’s been explained is Chaka’s post about the ideal KV to battery voltage (though I appreciate he doesn’t delve into torque requirements, hence my question).

Why is 192KV best for a 95kg man like myself? can I not make do with a higher rated KV? Could I go higher but need to provide the board with a push-start?

I weight about 70kg and use a 430kv motor. This is way to much top speed and way less torque. Sure you can increase the kv but then need a push start. But if this isn’t a problem you can go with a 245kv motor instead of 192kv. But the torque won’t be better since the 245kv one is shorter and has more kv

I am only saying, that with a 192KV motor you still get good speed for regular commuting, but also have the torque for a standing start. Not to mantion, that maybe in the future you will want to go 10-12S, and for that voltage 245KV will probably be too high.

How fast do you want to go? Just asking because 192KV on 9s can get you up to more than 35km/h. If you want much more, and don’t mind starting with a push, you can get the 245KV, it’s your choice.

Are there any smaller hills or inclines near you? If yes, that might be another reason to go with the lower KV.

Hope this helps!:slight_smile:

Instead of buying that motor on hobby king perhaps you could join our group buy…its exactly for the same motor but it is being bought directly to the manufacturer (no hobby king intermediates) and therefore you can save a few dollars.

Rough idea of it:

Higher voltage = lower kV

Lower voltage = higher kV

Because kV means rpm/volt it would mean if you raise your voltage you need to lower your kV to keep a good torque/speed ratio.

TL;DR for 10S the ideal kV is around 180-190 so if you go 9S you increase the kV to keep the torque and speed the same

@Ronny_CTS I believe @Youssless is based in the UK. Is there an option to the uk? I would be interested if so?

you can get as much torque from either it’ll just take more amps from the 245kv. if you want low speed torque you can also adjust the esc motor amp setting. id just get it and you wont have a problem with the adjustability of the esc or cogs if need be.

Thanks but where did you get the figure from? I’m only asking since it contradicts what Chaka’s post was talking about.

Indeed, good memory.

Unrelated to your motor question, but just so you know, you will probably need to cut off a piece on both sides of your hanger if you’re going with caliber trucks and enertion wheel pulleys due to them having an integrated bearing.

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Ooooh, this is something I forgot about. Is the mount only compatible with caliber II’s? I think there was a guide I’ll search for.

Which motor mount are you planning on using?

Enertion, bought it from the same guy I got the VESC and remote from.

Here: https://www.electric-skateboard.builders/t/sale-uk-vesc-motors-mounts-wheels-enclosure-gt2b-wheel-pulley-kits/21191

Enertion motor mount only fits caliber 2’s. What trucks do you have?

Don’t have them yet. Trying to find caliber II’s that aren’t £120+

I’ll need to saw off part of each side?


@longhairedboy cuts calibers on a daily basis and I’m pretty sure there are some guidance in one of his build threads

Wow thanks!

I’ve been looking, I’ll need to see if I can get my hands on the right tools. Checking @longhairedboy’s builds to see if he mentions how much to take off (roughly).

Here you go