Rubber mounted Harley-Davidson V-Twins use the engine as a structural part of the chassis. When the engine is removed, it becomes impossible to roll the motorcycle. This can incapacitate a lift or, at the very least, tie up floor space. Jims Rolling Buddy plates are designed to take the place of the engine and literally bolt the chassis back together and will allow you to roll the bike again, making your workshop more efficient. As with all Jims USA tools, these are tools for professional use, but are great for do-it-yourself use too.