For some of us, riding with a cyclometer of some kind is part of our fitness regime, or just being anal-compulsive, or whatever. I do track my mileage. On the other hand, moving cyclometers from vintage bike to vintage bike is a pain (I have an Avocet rig on most of mine), and it's hard to remember which cyclometer is set for which wheel size, etc. Then there's the hassle of taking the senders and such off for real vintage events. After a year of use, I'm ready to recommend an alternative: At the recommmendation of our son, I bought a Magellan ForeRunner 201 GPS system, which I mmount on the handlebars with a round of foam pipe insulation. No calibration required, moves in seconds from bike to bike, weighs little, and is easily read. It's even possible to xfer data back to the PC, although this one requires a cro-mmagnon "serial" port (I don't bother). Drawbacks: takes more handlebar real estate than mmost cyclometers, and battery needs recharging after every ride; claims to get only about 14 hr. Not a good choice for RAGBRAI campers, but I really enjoyed having it while riding a fixed-gear century on the old Paramount. Just would have been too much work to hang an avocet on that one. Indeed, gradually the Avocet senders and magnets and stuff are peeling away from my bikes.
harvey sachs mcLean va. No I did not check to see if that model is even offered still.