My old commute was 13 miles one way. What i noticed is that the bike (chain, wheels, etc) gets very dirty & grimy, with that mileage you're going to put on. Make it a point to clean off the chain & all the components every other day, and on weekends or whatever days you don't work, once a week, give it a _good_ cleaning. You'll also want to check for chain & brake cable wear. A clean, well-maintained bike is a happy bike!