just picked up a new fuji classic track with 46x15 and it is killing me. i have not been on a bike since my late teens and now that i am 39 i am severely out of shape. the 46x15 is 80.9gi and would like to get down into to the lower 70's ?

just looking for an opinion on what to try, i can keep the 46 and pop for a 17 and that will get me to a 71.4gi.

my city is mostly flat and i and out of shape. went for a 1/2 mike today and thought i was going to fall down when i got off the bike from my jello legs ! LOL