OK thank you 
I have another question : Actually I'm using a 36V battery. If a change for a 48V will I obtain more torque ?
Ive bumped heads with a few over at ES with this question.
Sure you get more torque. A you will feels it too, its not off the mark torque. The performance charts suggest ineffieciencies at 27nM loads at 48v. the 36v wheel actually pulls more nM at 36v than at 48v.
However.
Often power and torque are confused. Sure you get more torque at 48v in an area that you don't use yet. This will be much felt at the higher speeds you can not experience at 36v.
Looking at the performance curves on the GM site with a 26nM the 36v MP is giving about 180 rpm and at 26nM @ 48v it is giving 280 rpm.
The 48v MP lose over 80 rpm and the 36v MP will loose 75RPM under the test load, this maybe showing either the power limitation and added losses more volts oputts into the iron core of the formers..
In the winding all these volts can get pushed into torque under a high load. From 24v to 48v you can get an added 6nM at take offs..
Usually the motor can not put out much more torque than the windings can handle but we humans can convert torque to speed or vice versa. The new stuff I am learning here is Rider experienced torque to motor output torque. They are 2 different things to consider.
Just because one put gears on a motor doesnt mean the motor will give more torque, The wheel will and loose RPM doing this and nM reamains similar.
So I state, yes more volts gives more torque, a lot more torque at 45kph than a 36v config will give.
You feel the power more when it doesnt slow at 35kph and keeps going faster.
