I don't ride with a computer - a speedometer plus a bunch of other bells and whistles depending on how much one spends (including in the $1000+ range, if you want to measure your power output).

I don't ride with one because I could see myself staring at it too much - twenty four? hmmm. i can be going twenty six on this section. UH OH TAXI! - and possibly getting myself into dangerous situations.

I also don't like to think too much about data. Even getting into racing and "training" (scare quotes to differentiate it from an actually serious training regimen), I try to remember that it's supposed to be fun. I succeed, too - I backed off of alleycat racing when it was getting stressful. There were too many races that I wanted to do, and I started doing well enough to be disappointed with myself when I didn't do even better. That's when I realized that a) I felt like a dickhead to myself and b) it would be really dumb to get hurt doing a sport that I wasn't enjoying because I was too busy trying to win because I had gotten in the top five in some other (very different) race.

Where was I? Oh, right, not having any data. Until recently, that is - I clocked 13.84 seconds in my first flying 200, which gives me an average speed of 33mph, which makes me say a) daaaaamn, okay; b) what would my Mom say? and c) I can do better.