Just to clarify, I'm not some sort of "Xtreme Commuter". I absolutely agree that people need to ride within their confort zone, and they also need to think about what they're doing before they do it. I know people that get freaked out at the prospect of doing 25 MPH on a bike. If that's where they're comfortable, then so be it.

I'm 45 years old and last year I put in roughly 5500 miles of bike commuting. I try to ride as a vehicular cyclist, ie I ride my bike like I would drive my car or ride a motorcycle. I use the bike lane when it's appropriate, and I'll take the lane when it's appropriate. I stop for lights and I wait in traffic. I just happen to have a couple of nice descents that lend themselves to letting the bike run, if you will. Nice downhills with no cross streets in the middle of the hill.

I would never consider doing 50+ MPH on a road I didn't know really well, on a bike that I knew really well. I build up my own bikes and I ease into things before going for new personal speed records. I've flown in planes that I worked on, and I've gone scary, stupid fast on motorcycles that I built up. I've also taken a few high speed tumbles over the years, so I know what that feels like, as well.

The times and places when I choose to go quickly have been thought about in advance. These descents don't require any great degree of technical skill on my part. If you're on a decent, well maintained bike that doesn't exhibit any wierd behaviours (like a high speed wobble) then it's a lot of fun. But again, I know the equipment and the roads quite well, and I'm well within my comfort zone. Otherwise I sit up and ride down at what I feel is a safe speed.

Like they say, Arrive Alive!

--Marcus