I've managed to get myself a 2nd hand cross bike with cantilever brakes. i need a new stem but for some reason the guy who had the bike before me drilled a hole through the existing stem to feed the brake cable through (novel idea) so if i change the stem to a shorter one, i will have nothing to hold the brake cable. So, what is the thing called that goes under the headset that holds the brake cable in place, and where can i get one from? do wiggle sell them?