**induction**motors and

**brushed**DC motors. You can learn a lot from this.

If you're not the techie type, ignore the mathematical formulas and just look at the pictures.

http://www.reliance.com/mtr/mtrthrmn.htm

Here's a resource for

**brushless**motor theory for engineers:

http://www.drivetechinc.com/articles/curbldc3.pdf

another nice one here:

http://ww1.microchip.com/downloads/en/AppNotes/00885a.pdf

A more basic explaination is here:

http://en.wikipedia.org/wiki/Brushless_DC_motor

A nice animation of a brushless motor:

http://www.electricwheelscompany.co.uk/brushless_motor.html

To calculate speed, acceleration, current, and voltage, the famous 4QD calculator:

http://www.4qd.co.uk/faq/current.html

another excellent simiulator to help evaluate how different motor, battery, and controller combinations will perform on an electric bike:

http://www.ebikes.ca/simulator/

A tutorial on motor calculations: http://tinyurl.com/323cjr