Ask the Editors: Best ATV Frame for Building a Custom
Well for starters, no matter what ATV frame you decide to go with, plan on EXTENSIVE modifications to be in order for success. Naturally you would have to nearly completely start over with the motor mounts, do a lot of custom exhaust routing and undoubtedly lengthen the swingarm to transfer that much torque to the ground.
All of that being said, custom fabricators we’ve talked to said your best best is the Yamaha Banshee chassis. The reason? It’s a fairly spacious frame designed around a compact 2-stroke. The size of the engine bay allows for the wedging of a larger motor without encountering near as many relocated frame spars.
Your other option, which would actually be less labor intensive, would be to convert the motorcycle chassis itself into an all-terrain design. From our searching, it appears this has been done successfully by a few custom tuners around the web.