Think a 36 volt brushed motor on a beach cruiser can get me 4 miles with a moderate amount of hill climbing?
It probably will. Depends on what you mean by
moderate hills, your weight, battery, chemistry, amps, etc.
My first bike was a BL36 Wilderness kit with 12amp batteries that would carry my 240 lbs and a very heavy bike about 18-20 miles with no pedalling. However, my terrain is all flat.
Maybe a little more description and folks will chime in.
EDIT: Try this for info
http://endless-sphere.com/forums/vie...t=hills#p81957