APC hubs are designed to greatly reduce the amount of flex between the wheel race and the hub. With the lateral loads continuing to increase, it has become apparent that the wheels are now moving and/or flexing at the hub face. This movement is due to the limited amount of contact surface between the hub and the wheel, which results in a visible imprint of the hub into the back of the wheel and often loose wheels. To address this issue, we have greatly increased the contact area of the hub face. We have field tested these hubs for the past few months with great results. Racers even say that the lug nuts stay tighter than with the old design.