Originally Posted by Salamandrine

The clicker type were more common. A lot of people used and liked the clicker ones, maybe you will too. It would annoy me, so I vote for the wheel. However, I don't have one of those and I can't tell you if they work well or not.

I used to have an IKU speedo BITD. Those work quite well. They have a little red plastic wheel the rolls on the tire. After a week or so of tweaking the position of the wheel, I got the odometer on it to match up pretty much exactly with the mile markers on the road where I did my usual after school training ride. IKU speedos come up pretty often on ebay, and they go for cheap. Clearly it is obsolete tech, but I find mechanical speedos and odometers interesting.

BTW, If you have any interest in the IKU make sure you get the light road version that goes to 100kph, not the big chrome 'muscle bike' one.