1/4 Scale Tire takes a 5/32(4mm) Axle. Add the realism and final detail to your J-3 Cub with Du-Bro's Treaded Lightweight Cub Wheels. These J-3 Cub Wheels offer bolt together hubs and realistic looking Cub wheel covers. Available in three sizes, these lightweights feature a foam interior, yet have a tough and rugged exterior skin for durability.