The main features of a Schwinn 12 Function bicycle computer are a digital speedometer, odometer and clock. The computer records speeds, distances and times, allowing the user to compare tendencies and plan cycling strategies. A Schwinn manual is available online from K3pgp.org, explaining each of the 12 functions in detail.
The Schwinn 12 Function bicycle computer collects data via a sensor clipped to the front forks of the bicycle and a magnet attached to the spokes. Each time the magnet passes the sensor, the wheel's circumference is recorded as distance travelled. The computer collates this information with time data from an internal digital clock to provide accurate speed readings and performance comparisons on the move.