A few more details on this project in process.  The instructions say it
will read up to 99.9 km/hr or mph.  The trip time will go up to 9:59:59,
the trip miles will go up to 999.99 km or miles.  That could be a problem
on a long trip.  Not sure if it rolls over or explodes if you go past that
value though.  I glued the magnet to the hub with silicone.  It is holding
so far, but has only a few miles on it.

Edward