1) get a brake for stopping. please.

2) how does the 46-16 work for you on the 'going' front? acceleration is quick/ok/painful? top speed limited by strength or leg speed? let this determine your gear.

i run a 46-16 and am a fairly strong rider in a moderately hilly area. i ride the fix almost exclusively for training purposes. it's perfect at 20-22mph, too much on steep hills, and too little in a fast paceline...that's why there are derailleurs.

with that as background, if it were me, in a flat campus environment where acceleration trumps top speed, if i were foolish enough to endanger the safety of others by going brakeless...i would damn sure want a lower gear than 76 inches. 17t = 71in, 18t = 67in. go for the 18 and bust some madd skidz (9 patches, actually).