Spalding Cyclometer: Red 'RESET' triangle on left, yellow 'MODE' triangle on right. Back has 'SIZE' pinhole on left, 'SET' pinhole on right. SR44/G13 battery.
Does not seem to fit into the six standard calibration schemes.
A 26 x 1.95 tire (circumference 80 inches) registers somewhere around a 130 calibration number.
Does anyone know the actual calibration formula for this model?