What’s your top speed? I feel like my board reaches 30mph in around 3-4 seconds and I usually don’t even max out my motors
About 37mph because I geared it down as I didn’t need the speed
3-4 seconds to reach top speed sounds about right. And I like the idea of actually measuring in the real world how fast we reach our top speeds, because then battery limits come into play as well as other things, like, being able to control the board, in my case. 
I have current limits set to 30A per motor, because otherwise I need to hold on to the front of my board when starting up, but also need to stand up for control before max speed gets reached, and that’s too dangerous of a maneuver
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Haha same, I’ve lost traction on fast starts sometimes if the roads rough.
I tried to drag race my little brother the other week on his single motor board I was off like a rocket but he was lagging behind doing a burnout hahah
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Are you guys finding that acceleration is better in FOC compared to BLDC?
I feel that when the bldc reaches some momentum it really pushes hard 
Motor torque is calculated in calculator by diving motor power rating by maximum battery voltage for e.g:
Power Rating 3000W and at 12S maximum voltage is 50.4V so maximum current is 3000W/50.4V = 59.5238095238A (60A)
Torque is calculated by this formula:
so for 170kV motor torque with 3kW power is:
= 3.3Nm
The board has 1:3 gear ratio so we multiple 3.3Nm by 3 as gear ratios multiply the torque. We get 9.9Nm per motor at ideal conditions.
Now as we get torque (angular force) we can calculate the actual wheel to force:
By using this formula (for 200mm radius wheels):
F = T/R = Torque / Radius of the wheel
F = T/R = 9.9 N*m / 0.1m = 99N
Now we have force. By using F = ma formula we can calculate acceleration.
a = F/m = 99N / 100kg = 0.99m/s^2
So 50km/h will be reached by calculating this way:
Vf = is final speed Vi = is initial speed
Vf = 50km/h = 13.89m/s
so t =(13.89m/s - 0m/s) / 0.99m/s^2 = 14.03s
It would take 14s for single motor with 1:3 gear ratio and 3kW (60A) power to reach the 50km/h speed in the ideal world without any friction resistance and etc stuff and if you kept your throttle full power and motor was consuming full power 60A at all the time.
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I run bldc and when reaching about 15km/h it really pulls and I nearly shit myself every time
Couldnt describe it better haha. “im ready , im ready…Holy shit”…
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Just to understand how absurd these numbers are lets take my board for e.g.
Here is specs:
Dual motor gear drive kv: 180kV gear ratio: 1:5 motor current: 150A/ea Wheel size: 203mm = 101.5mm radius Full curb weight: 110kg
Nm/A = 60 / 2 * π * 185 = 60 / 2 * 3.14 * 185 = 0.05164400069 Nm/A
Nm (Full Power) = 0.05164400069 Nm/A * 150A = 7.7466001035 Nm (per motor)
Nm (After gear box) = 7.7466001035 * 5 = 38.7330005175Nm (per motor at wheel)
Force = 38.7330005175Nm / 0.1015m = 381.6059164286 N (per motor)
Total force both wheels = 763.2118328572 N
a = 763.2118328572 N / 110kg = 6.9382893896 m/s^2
so to reach 50km/h (13.89m/s) at best conditions
t = (13.89m/s - 0m/s) / 6.9382893896 m/s^2 = 2.0019343703s
All these figures are cool for comparing but I doubt any of us can reach 50km/h in less than 3 seconds
Plus ESC does not provide that exact power at start up sometimes its even higher current as at low duty 0.1 voltage is like 5V
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(In all seriousness, thank you for that thorough analysis!)
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I am looking for the best way to reduce my acceleration on FOCBOX Unity
If I hit the remote too hard the board will throw me off
What??? Jk, just lower your motor max current. Could also lower batt max if thats not enough.
i lowered battery max from 60 to 50 and that did help
is lowering the motor better?
what about the “ramp to start” and “ramp to brake” settings in the Unity Tool?
Motor max is basically the max amps that you can use at low speed, like when accelerating. Batt max is basically the max amps that you can use at high speed. Therefore its normal to lower motor max first, and if that isnt enought, you can lower batt max. This is obviously very simplifyed, but it kind of works like this. I havent adjusted the «ramp» settings, so cant say for sure.
It’s an interesting comparison… According to this, a 3:1 gear ratio with a 190kv motor 4wd would have about 36Nm vs my 28.66Nm.
But your leaving out key factors about the motor design that affect torque. I threw 30a per motor through the v1 hummie hubs and 30a through the new, double stator sized v4 hummie hubs, and the torque is completely different and much better. Same settings, same kv, same controllers, same battery, same voltage, completely different amount of torque…
Some of your force will be used to overcome pavement surface wheel frictional resistance and even more force will be used to overcome air resistance and the balance will be used to accelerate. and of course if you are going uphill there is force required to overcome gravity I have an excel sheet to calculate all of these
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Well apparently motor size doesnt affect torque output…aparrently
2.818 m/s/s.
Calculated, should take my board and my weight ~7 seconds to reach 70km/hr.
With real world testing it took me 7 seconds to reach 65km/hr, and another 5 seconds to reach 70km/hr.
So to answer OPs title, acceleration wise, no. Not a beast.
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