I've talked a lot about biking here, especially my own riding. Today I'm going to talk about the stuff that goes with me on a ride.
Some folks like to equip their bikes with a small computer, that can record their speed and mileage, and sometimes other data. These are battery powered, and connect to the bike by a wire that runs down to the bottom of the front fork, and ends in a small electromagnetic contact. A second, magnetic, contact is mounted on a spoke.
A good, light weight, computer can be an essential accessory, but I prefer something even more powerful, even more light weight, and less expensive: it's called a brain. OK, maybe that's a little pontifical. Let me elaborate.
A long time ago, I bought a small mechanical odometer for my bike. It mounted on the axel bolt (the quick-release, nowadays) of the front wheel, and a small knocker was mounted on a spoke. As the wheel turned, it turned the odometer's wheel, and advanced the mile counter. The odometer I bought was designed for a 27 inch wheel. And so, I knew my mileage after every ride.
The other piece of equipment I had was a $13 Casio wristwatch, with a timer. I set the timer when I started a ride, and turned it off at the end. And so, I knew how long I'd been riding. A simple calculation gave me the miles per hour, or average speed of the ride. That calculation could be made during a ride, too, as long as I remembered not to turn off the timer early.
This worked for a long time. In fact, it still works. A $7 odometer and $13 Casio are providing me with all of the information that a $77 bike computer could provide, at less than half the cost. There is an ongoing cost for pencils and small notepads to record ride data, as I do not have a computer's memory function.
Maybe one day I'll break down and buy a bike computer. Probably not. I'm pretty old-school about my riding. Also, while knowing my time on the ride, mileage, and average speed are good things, I can do without knowing my average blood pressure.