On the outside of the wheel you can place a washer, then a 1/4 inch piece of neoprene, then add pressure onto the fuel line with the wheel collar. The pressure acts as a slight break. Adding toe in on the LG also helps slow them down. If you have the room then doing shallow turns in an S will eat up more runway but if done too sharp you will be ground looping and hitting your wing tips. A Cub floats in for a landing so the landings should be slow enough that run out isn't a problem. A Cub takes some getting used to but after a few flights they are really easy to figure out.