another case o the premades... sorry no you generally cant modify a premade ebike, as per the manufacturer, would void warranty, safety specs etc. i wonder do folks consult the manufacturer first or find the first forum to post on. its ok tho happy to help. we almost exclusively recommend going with a custom mid drive motor kit on a quality mtb frame. in this way you convert a regular quality bike to an ebike. with a bafang or cyc motor kit, you can climb anything with ease, more torque, speed, and its quiet. the flexibility of changing kits over time, ease of maintenance make going custom emtb a better option than premade emtb/ebike. though it depends on what your use case is too. you might want any of the following: a simple commuter hardtail with a rear rack, a fat tire hardtail mud and snow cruiser, a fat tire full susp hunting bike, a trail alloy full susp emtb, a top end carbon full susp emtb. all of those will have different ideal motor and battery setups, pros/cons and costs.