It took me 15 minutes and 34 seconds to get home from work yesterday. Before this, my best time was just shy of 19 minutes. That amounts to a 17 mph average, exactly, over the course of 4.6 or 4.7 miles. If that doesn't sound very impressive, there are two hills that aren't terrible, but are long, and slow a Clyde down, so a fast ride including the hills isn't easy.
I'm not really sure why the difference is so huge. I've been training on hills a lot lately ( and cursing Mr Beanz the whole time! ), and I've been focused on staying in the big chain ring as much as possible, plus it was a balmy 80 degrees, making the air a little bit less dense. Plus, I don't sprint every day, and haven't in a while, so if I've been getting stronger lately, this is the first time I've tested it, and that could make the gap seem bigger...?
I can't make the commute home that quickly by car more than once every week or two, thanks to rush hour traffic. It's "fun" that I can go faster with my bike on the surface streets, than I can in a car on I-5.
When I got home, I was breathing pretty hard, but relaxed quickly, and felt good. The commute took little enough out of me that I went kayaking last night, although that wasn't very hard work. Anyway, I feel like it's a big accomplishment, and I've been telling everyone who'll listen ... whether they care about cycling or not.