Abstract: An all-terrain motorcycle attachment device for attachment to a two-wheel motorcycle to convert the motorcycle to a three-wheel all-terrain vehicle is disclosed comprising a swingarm frame adapted for detachable connection to the swingarm pivot bolt assembly of a motorcycle, an axle rotatably mounted to the swingarm frame and supporting a pair of wheels, a drive sprocket connected to the axle, a brake assembly adapted for detachable connection to the brake rod of a motorcycle and a mount for detachably connecting the rear shock absorbers of a motorcycle to the swingarm frame.