think about it, you're not going on some exploration where you are delving into the unknown. what would you carry on a normal 35 to 40 mile bike ride? bring that.
clothes? WTH? are you planning on going to a dance or club? bring a rain jacket. it provides warmth and not a lick of water repellant.
the one thing i do adamantly recommend is food and drink. bonk breakers, Clif bloks, clif bars, hydration packs...you get the idea. nothing will make your journey a nightmare more than bonking at mile 75.
BTW, BEER = GOOD!