Lovingly hand built about 25 years ago and ridden to death ever since, the odometer is showing some 1800 miles which is what I put on it since I replaced the speedo a couple years back.
The Cateye speedometer works great except that it was designed to be mounted on conventional handlebars, i.e. perpendicular to the direction of travel. My bars are mounted under the seat, so this is impractical. I mounted the thing on the frame backbone using a kluged up mount which got kicked apart at the Maker Faire.
Cateye may well make a mount for recumbents, but where's the challenge in buying someone elss ready-made solution? This one:
is simple, secure, and works fine. If it gets kicked, it rotates around the frame and is easily rotated back where it belongs.
Yes, the paint is badly scuffed up. The bike gets a lot of use and when I can't ride it, it's too cold to be painting in the garage. If there's any interest, and I learn how to use the Google store-pictures-here-for-public-access thingie, I'll put up drawings of the parts.