Optional on all Forgeline monoblock competiton wheels is knurled beading. A knurled bead seat is pressed on the rim in order to reduce the slippage ratio between tire and wheel. This maintains the best position of the wheel and tire assembly, thus achieving the highest performance during extreme acceleration and deceleration. Although the knurling will help minimize tire slip within the wheel, it will not completely prevent slippage in extreme high torque applications. The knurled bead seat is also an option on most monoblock wheels that do not already have them yet, just return the wheels to Forgeline. This upgrade benefits motorsports/ track applications and is $50.00 per wheel.