Jacos are the exact same size as the stock wheels and tires. There is NO ballooning and the grip is excellent. Wear is also superior to regular rubber tires. When you buy them ,they come mounted and glued and trued. It's too bad I didn't find them until I burned 2 sets of stockers and a set of Anacondas up. Just go to Jacoracing.net and get details. They are available on Tower Hobbies.