I agree with the Fixer on this one. There shouldn't be a real need to swap out anything on your way up there. I ride 41x14 and I can make it up there no problem.
The real issue here is, how do you ride fixed in Highland Park and I not know who you are? I used to live there like six months ago and could have sworm me and my roomate were the only fixed riders in the area. Wierd.