I also don't think I really save anything. I do it for the fun and the challenge. It's a 17 mile ride in one way. I get up at 5:30, and I'm rolling somewhere between 6am and 6:30, takes me 55 minutes to get to the office with stoplights, traffic, etc.

My alternative ride is my Suzuki V-Strom 650. Gets 50mpg, costs $200 a year to insure, tires last 10K miles, chains last 20K... it's probably about even with the bicycle.

What kills the savings is buying stuff. I enjoy gear that works well, so even though I have a nice "900 lumen" light, I'm still reeeaaally trying to resist getting the updated Philips Saferide light when it comes out for 2013. Stuff like that (nice Planet Bike winter gloves for $35 that work really well, PB toe covers, knee warmers, etc). That has slowed down a lot though once I buy something I'm satisfied with, so maybe that's just a bigger initial commuting cost. Cycling has always been my passion, I'm 31 now and I've been really cycling since I was 14, so it's not a fad for me. That's one way I justify it. At this point I don't care if it "costs" me a little more, too, because I arrive at the office energized, and I get home in a good mood 95% of the time. A big part of that is being slower than the rest of traffic... things that would get me fired up and angry on the motorcycle when others drive like idiots would always put a damper on my day. Now? If I get angry, I pedal harder for a bit, might swear a little... but it melts away. It's a great feeling, hard to put a price on that.