I don’t think it should. The cruising speed that you will want to use most of the time should be below the max voltage of the motor.
You like 6S better than 10S? Or were you only talking about higher KV?
What type of Esc are you planning to use?
Haha ik but yea I really did prefer the 6s
I’m running dual 190kv at 10s with 15/36 gears and 83mm wheels. What I have noticed is that this combination seems to have a good balance between torque and speed while the motors never get hot, warm sometimes but not hot. Neither do I have any problem with the Vesc’s over heating even when going up and down long hills.
2 Likes
Don’t lower KV motors have more copper in the stator?
I’ve a tool to calculate things like this, just put in paremeters and see how speed etc. changes. It also shows motor RPM and max current for the given motor watts. It doesn’t show torque directly but it shows the force on the street. (torque is at the axle, but force depends on wheels size) http://esk8-dresden.de/poe/v0.2/?tree=18650,Battery,Li-ion,1S1P,4S,5S,6S,Single,Dual,Belt,MotorP,WheelP,Wheels,70mm,75mm,80mm,83mm,90mm,&cellweight=45&kv=280
3 Likes
How to take into consideration the wheel size for this?
I get about 45 ‘direct’ kv, when I divide 192 / 4.33 (ratio). But im having 9in pneumatics + belt drive.
I assume, in general, pneumatic wheels will require a bit more torque compared to street wheels
@NNGG I’ve heard the opposite from some people so I’m not really sure. I figure it probably changes for each type of motor. I suppose you could look at the weights of them to see if one has more copper than the other. For SK3s the 149kV weights 1265g and the 192kV weights 1288g so I don’t think you’d be able to feel the difference.
@Okami Upgrading the diameter of your wheels would raise your top speed. If you compensated by increasing the reduction ratio in order to keep the top speed the same than theoretically the torque would be identical. However I think you’re right in assuming that pneumatics would be less efficient so to keep the same amount of torque you’d have to increase the ratio a little more.
1 Like
Any of you who have used High vs Low KV noticed more DRAG on the lower KV motors…Does not coast as freely as higher KV, probably lowering Range as well ?
Just heard about this on another thread and am curious about others experience ?
Thats correct at higher speeds, coming from a 149kv @ 12S, But I don’t notice it at sub 20 kph
Sorry for the late response, I am going to use Turnigy k force 120A hv esc that I have used to run this motor in the past. Mostly because I have it lying around. I will eventually switch to the VESC because of the improved start up torque and more advanced setting for regenerative braking.
We will see if it can handle the load. I will work out the electrical and mechanical efficiency to see how bad it is. I know with the added reduction I will have some mechanical losses but hopefully not a ridiculous amount.
6374 190kv with a 12s is scary fast gold to the small amount of knowledge I have… Motor only get slightly warm after some good abuse. Granted its only 40 or 50 degrees now, but I can tell it’s a very fast, reliable setup for the short time I’ve gotten to man handle it.
Latly im very interested in a higher KV lower Series battery, mono setup too.
Just really want to know what I’m getting into before I pull the trigger.
The price of 6s-8s batteries are nice with a mono set up.
Is it just about the same sensation as my own setup? Without the high speed? A much more calm controlled ride all around?
Thanks 
Also in the process of building my dual motor 6355 190kv now on a 12s4p from Bara… Got everything but the enclosure here or on the way…
So I want something different for my girl or a friend so they don’t feel like they’re on a rocket to outer space
Using a scorpion 5030 220kv at 10s and can reach 28mph easily on flats, don’t recommend because it does cost $300 new
That’s assuming it’s an out-runner with 14 poles. The T20 he’s using is 4 poles. ERPM = (720KV)* (12S * 4.2V)*(2 Pole pairs) = 72,576 Max ERPM
PXSS is correct this is a 4 pole motor. 72576 ERPM
720kv inrunner at 12s 128amps? What size? A 56mm+ inrunner geared down correctly would have stupid power, but would require some fancy gearing to harness that power at usable board speeds. I’d love to see you pull it off and I’ve been toying with a similar idea myself.
If you run 90mm wheels, you’re gonna need to gear it down 7:1 or somewhere thereabouts to get proper torque off the line. With that kind of ratio you need a gearbox, or multiple reduction stages if you stick with belts. What’s your plan for gearing?
Hey HTownBomber,
Yes it is a 56mm inrunner that runs 12S @ 128A. I agree with you the biggest challenger is the gear reduction. I should be done and riding the streets by the time the snow is gone where I live.
I am running 90mm wheels. I would have liked to go to a 7:1 reductions but I am starting out with a 6:1 due to space limitations. I am using a two stage system. A pulley mounted on the wheel will be driven by a pulley mounted to a small 3/8" OD jackshaft bolted to the rear truck. I am using roller bearings to hold the shaft, which are rated at 650 lbs and 29,500 rpm. I will use a hardened shaft so it can take the load. The other side of the jack shaft will have my second reduction which I have already purchase. This reduction is a set of high load 20 degree pressure angle spur gears at 2:1 reduction (24 to 48 tooth). The 24 tooth is mounted to my motor, the 48 tooth is on the jack shaft.
I have to make sure I can still adjust the belt tension, or alternatively add a belt tensioner as an add on.
Thats basically my gearing plan. I might weld a small SS box around the gears after I am happy with it and fill this with grease or oil, otherwise my only concern is that the gears are going to get HOT.
The motor I think i can keep cool with the water jacket. I have used this motor on a BAJA 5T before and I still have the small radiator/fan and water pump i used as a closed loop cooling system on that project. I am going to use a similar system here.
Results from the spreadsheet I used for speed calcs below.
7.42 ft-lbs of torque at 104 km/h…crazy but not impossible. Iv gone that fast on my snowboard, never a longboard though. 104 km/h downhill seems sketchier then powered on a flat run.
Cheers,
Chris
I started my own thread on the build portion of this forum. I will be updating it tonight with some pictures.