In a thread below I read about reading the speed off the left front wheel. I cannot find any thing in the vendors websites about how to mount the sender or how they work. The cable on my 5303 broke the other week. Any advice would be welcome.
There are GPS speedometers starting at under $100. The nice ones are a good deal more though. I recently bought a tach from this guy http://www.precisionspeed.com/. See what he has to offer.