I looked at this too. It looks like a great bang for the buck. I'm pretty sure it can be adapted to any bike. You program in the size of the tire, and there are lots of mounting options.
I chose a GPS system instead. Take a look for the Garmin eTrex line. The most basic unit is around $100, and the handlebar mount can be had online for $20.
It does the same things, gives you distance, speed, and offers more in the way of: a compas, waypoints for your favorite trails (and so you don't get lost). Waypointing the car and heading off without worrying is a good thing.
I originally had the cheaper one (yellow basic one) and gave that to my dad and upgraded to the Vista. It contains maps and comes with the PC cable to you can 'chart' your favorite trails and save them on your PC. (you can do this with the basic one too, but the vista has more memory and can hold more).
my .02 cents.