I went to my local "Bicycle shop" and purchased a digital bicycle speedo. Mounted it to my handle bars made a part for the magnet to mount on my spokes. I also had to make a part for the front fork and lengthen the wires. Speedo cost me $25 and some custom made parts. Take the circumference of the wheel divided by 3.14 and that tells you the inches of your tire. Put that in the speedo and it works perfectly. Even has a clock. You should see the looks you get when someone sees it. My wrench who inspects the bike laughed like crazy until he took it for a ride, then made one for a customer.
The down is no running light and when you change batteries you loose the mileage.
The down is no running light and when you change batteries you loose the mileage.