A method of forming a tread comprising two or more layers of rubber is described. The method includes the steps of: extruding a rubber compound through an extruder and a gear pump and mixing with an accelerant and then applying a continuous strip of rubber directly onto a tire building machine to form a first layer of rubber having a first cure rate; adjusting the amount of accelerant to obtain a second cure rate different than said first cure rate, and then applying a strip of rubber having a second cure rate onto the tire building machine, wherein one of the cure rates is faster than the other cure rate.