I don’t really understand the advantages of a 48v over a 36v motor. Are 48v motors not more robust and longer lasting? What I would like is long range ability, maybe 40 or 50 miles and low front hub weight. Does range depend on voltage or battery capacity?
They're the same, so there is no advantage. The advantage comes when you run whatever motor at 48v. At the same current, you get 30% more torque from 48v, or you can use 30% less current toget the same torque as running at 36v.
Let's say that you have a 36v 260 rpm motor and a 48v 328 rpm one of the same type. At 36v, they will both give identical performance - x amount of torque and 260 rpm max speed. At 48v, they both give 1.3x torque and 328 rpm.
Let's say that you have two batteries. One is 48v 12 ah 13S4p (52 cells) and the other is 36v 15ah 10S5P (50 cells). Whichever battery you use, both motors will give approximately the same range as each other. To be precise, the 52 cell one will give 4% more range because it has 2 extra cells. On a ride at full power all the time with a 15 amp controller, either motor with the 48v battery will give 30% less range than the 36v one because you’ll be using more power and getting more speed, assuming no limit set.
In the real world, you ride with the amount of power you want. 48v gives the potential for 30% more torque/power, but most of the time you don't use the extra power, so not much effect on range, but if you have a lot of hills and turn up the power to max, then range would be affected more. Range depends on how many watt-hours in the battery when you start and how fast you use them up. 48v has the potential to use them up faster, but how fast you use them depends on you.
