I need to know about the torque required for my electric Motorcycle Conversation. Weight is around 200Kg (Including Rider) Tyre diameter is 20 inches Acceleration required around 0-100kmph in 15 sec.. Though I have no idea about inertial force and frictional resistance whatever it is.
Please help.
If we Ignore drag, mechanical losses and slip of your tires:
Your desired speed is:
100km/h * 1000 m /3600 sec) = 27.7 m/s
You need a total work W of
W = 1/2 m * v² where m is mass and v is velocity
So you need a total ~384 Nm over a time of 15 seconds
= about 26 Nm per second
Now you need to determine total transformation ratio of gear + drive train + wheel and find a Motor that delivers the appropriate torque to the wheel over the whole rpm-band needed for 0-100. Don´t forget to add drag and losses of your drive train. Also max. power rating of the motor/electronics could limit torque at high rpm.
Let's use a different approach, let's calculate the kinetic energy of the vehicle at 100km/h:
Ke = 1/2 * m * V^2
0.5 * 200 kg * ((28 (m / s))^2) = 78 400 joules
so if we want to do work for 80000J in 15s we need a power of:
80000/15 5300W, or around 5KW.
Considering losses and air drag a 10KW electric engine should do the trick with the proper transmission system. This is a rough estimate but I think it is not far from being correct.
