Wheel hubs are a great tuning device that can be changed quickly and easily. Use a shorter hub to gain grip and get the kart to 'come on' faster or use longer hubs to get the kart to 'come off the corner' better. Use wheel hubs to gain in different areas to axles and as a way to get an in between axle grade change when needed.
Magnesium hubs also offer a different feel and grip level to aluminum due to the stiffer nature of the magnesium material. In recent years magnesium has become a popular choice for 50mm wheel hubs often offering improved performance.
Use Kartech Wheel Spacers to easily adjust rear width and prevent hubs from sliding on the axle when driving.