Thumpin, I got my topeak from, www.trailtech.net
back when they were relatively new. Back then it was only something like $50 or so. But now it's becoming a bit more popular and I've seen a few around and their price rose and is now $75 on their website. I found it at rocky mountain for a $5 less, no biggie, but here's the link, http://www.rockymoun...sp?sid=00494645
The one you found is a bit different and just set up for bicycles, the topeak kit comes with heavy duty mounting kit, and the whole sensor kit which needs to be longer to reach down the forks and to the caliper. Check out www.trailtech.net
there's a lot of good info on there. It's an awesome little computer, and it's great to be able to just look down and see your speed and then check your average and max speed at the end of the trip. The odometer and trip meter are pretty cool too and it's nice to always be able to tell the time. Back when I first got the kit and installed it, I found the display to be a bit slow to update the speed because the sensor needs the magnet on the rotor to make a few revolutions to pick up the speed. So I talked with Trailtech and they send me out a few more magnets and epoxy. I put on another magnet and set the wheel
circumferece in half on the computer and the display was a good deal quicker and definetly suits my needs now. It's still not totally quick like an analog speedometer, but works fine. The odometer and everything is still extremly accurate. It was a breeze install and comes with everything. Trailtech's customer service was great and had no problem with sending me out a couple more magnets and epoxy free of charge to experiment a bit with the display speed. If you have the money, I'd say it's worth it and would efinetly buy mine again. Really cool little gadget and works great. Let me know if you have any more questions.