I'm thinking about putting a 700x32 tire on my back wheel. It's a surly pacer frame, so it definitely has room for the 700x32, but I've got tiagra brakes it which I are 39-49 mm reach.

The bike currently has a 700x28 panaracer t-serv on it, and I'd like to go up to a 700x32 tserv. If the measurements are right, I'd need another 4 mm on top & 2 mm on either side to go to the bigger size tire. I definitely have it on the sides, but on the top of the 700x28 tire to the bottom of the tiagra brake, there's about 1/4-9/16 of an inch of space which is 6.35 mm assuming that's the smallest... That gives me 2.35 mm to spare. Is that enough or is that cutting it too close?

Anyone else running 700x32 tires in standard road brakes?