Most of your weight happens to the back tire. On Cronus,my yellow Titan and my main bike,my rear wheel has gone thru three wheels and about 5 tires while my front wheel and tire remains factory stock.
I just get my tires at the Wal Marts. But my tires last me a bit longer than 200 miles.
I would say I can get almost a thousand miles a tire but I do alot of cruising I say it's equivalent to having highway miles on your car.
The less weight in back the better. Sometimes I ride standing up I seem to think when I do this more of my weight goes to the front and less on the rear.