Originally Posted by Doc_Wui

Look on ebay and you will find any number of 24V ebike controllers for under $24 shipped. The problem will be figuring what controller, and then figuring out all the connections, but you can get help for that.

First thing to do is count the number of wires to the motor. All will have 3 bigger wires, which are the phase wires that power it. Most motors will also have five small wires which will be for sensors. If it is one round cable, then unplug it and count the # of pins inside.

If the five small wires are not there, you buy a sensorless controller. Otherwise, buy a controller with sensor control.