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Problems with Votol Em200sp and low acceleration.

Apr 13, 2023
Hi guys!

I'm Marco from Spain.

I've built an electric dirtbike starting with a gasgas 450cc dirtbike and I installed a votol kit. The kit consists of: votol em 200sp controller + qs138 90h motor + custom 72V 20S10P 250A max discharge the battery. I'm running a 520 chain with a 13t/48t gear reduction.

I've made some posts asking questions because I don't quite get the acceleration I wanted or expected the bike to have and I have some theories.

1st theory. Looking at the torque graph for the motor, it starts giving max torque at around 175rpm, which equals 15kmh with my gear reduction. You can feel that, because when you give full throttle in the 0-13-14km the acceleration is way weaker than at 15kmh, because at 15 you can feel the wheel lifting off.
Following this theory, going up to a rear sprocket of 70t, would move the max torque delivery to around 5kmh, resulting in a way faster acceleration...

2nt theory. Maybe some parameter is off. On page one my parameters are Busbar current (550A), and phase current 9960. Start torque 1000, combinative torque 0, rate of rise 250, and rate of decline at 85. On page two, sport mode current limiting, at 550A, flux weakening both values at 200. The three-speed box, hige is 100/100. The third page is as it came, with no changes. My question here is if anyone knows what phase current is and how to adjust it.

Thank you all a lot!


  • Torque.png
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Presumably you already have this manual. If not, does it help you? My experience is that some portions are helpful but other parts contradict or simply use incorrect wording and therefore the meaning is lost.


  • VOTOL EM Motor Controller Manual ENG V3.4- by SiAECOSYS.pdf
    2.5 MB · Views: 30
Max torque at 175rpm, that's motor rpm, not output shaft after primary reduction? I'm guessing motor rpm, iirc the 90h doesn't come with primary reduction so if you're doing 15kmh at 175rpm then that's 85.7kmph/1000rpm... you're geared for about 260kmph before the field weakening kicks in??