A:Answer For 320lbs, you'd want to upgrade the seat to a bigger aftermarket seat, better shocks with a heavy coil spring to accommodate the weight (maybe 700-800lbs), seat riser, lifted handlebars, and the battery won't last long or have much power, so you'd want to upgrade to bac4000/8000 controller and get a 72v battery, so you're talking about adding $6k-$7k+ in after market parts.