Shimano's Dura-Ace groupset is the top o' the heap, but it won't work to its full potential (and thus won't be worth the investment) if you run it without the Dura-Ace BC-9000 Polymer-Coated Brake Cable Set. By combining a polymer-coated stainless-steel cable with a pre-lubed housing, this set gives you braking that's smoother than buttered silk and more reliable than the sun coming up tomorrow morning.