A remote control motorcycle is a great summertime toy. Many are best used on paved surfaces, but some can be used off-road. The linked page has a couple of super-cool videos of rc motorcycles in action so you can see what they can really do. These can be set up quickly, but are also very upgradable. They handle crashes quite well. Crash bars are used to help keep the rider and polycarbonate motorbike shell from getting scraped up too much in crashes and also help the bike to right itself to resume running without you having to get over there and pick it up yourself.