To actually answer your question, benway0007, magnetic pickups for the speedo are very common, as are electronic tachs. Most electronic speedos can be programmed for the rolling diameter of the wheel they read from; some have a Hall effect pickup that threads into the speedo drive in the front hub, some have a pickup that you secure to the fork or swingarm and a magnet that you install by drilling into the head of a brake rotor or rear sprocket bolt. Vapor (from Trail Tech), Veypor (from Nonlinear Engineering), and Acewell (from Electrosport) all make digital instruments with tach and speedo functions, and all are programmable for rolling diameter (speedo) and pulses per rpm (tach). I use either a Veypor or an Acewell, pretty much depending on the mood I'm in. If you're using an ignition like the Probe that has a tach output wire, any electronic tach will give you clean readings. Otherwise it's best to hook up the tach signal wire at the neg. terminal of the coil. The Veypor has programmable filter levels for the tach signal, to damp any spiking. With less costly units like the Acewell, a 2 megohm resistor stack is needed after the coil to get clean readings.