This is a simple design that locks the outside of the tire and seats the other side of the tire in a groove. This Design is mainly intended for trail crawling; however, you are free to test it for comp crawling, I would appreciate any feedback.

The screws used are M4 25mm (~ 1 inch) cheese-head screws; however, if you have hex head machine screws of the same specifications it would be even better. Note that this design is intended to be simple, so don`t expect your tires to be vacuum rated, and are mainly for use in arid and dry environments.