Burnt75 said:
Thanks Dogman. Most helpful. Trying to decide between 3000 or 5000 motor. Would like mostly to ride about 25 to 35 mph with some fun run of about 45mph.
http://www.ebikes.ca/tools/simulator.html?bopen=false&motor=MX4503&batt=B7223_AC&cont=cust_50_115_0.03_V&hp=0&wheel=18i&mass=110
Buy the MXUS 3000W V2 or V3 they are both excellent choices. Get the 3T and lace it into a 17" motorcycle rim, with Shinko 244 tire. Install suitable battery which will be 20S 72V(nominal) 84V(max) for your 45mph requirement. The smaller wheel diameter allows you to keep everything cooler. Take a look at the motor simulator, fits your needs perfectly.
This is with a 5% grade added, and you are still flying fast, over heat in 39 minutes, at 62kph which is like 38mph.
http://www.ebikes.ca/tools/simulator.html?bopen=false&motor=MX4503&batt=cust_82_0.2_8&cont=cust_50_115_0.03_V&hp=0&wheel=20i&mass=110&grade=5
Controller - If you want to save money, buy the ebay seller hksunwin he sells 72V 1000W on up are all the same, there is no difference between them.
https://www.ebay.com/sch/m.html?_odkw=48V&_ssn=hksunwin&_armrs=1&_osacat=0&_from=R40&_trksid=p2046732.m570.l1313.TR12.TRC2.A0.H0.X72V.TRS0&_nkw=72V&_sacat=0
Where to buy your battery and torque arms - http://www.ebikes.ca