We are here to help you For quick and easy service, contact us:   Phone:   630-761-1106 Fax:   630-761-1107 Toll Free:   888-744-6277		BC 400 (1997) What can cause the bike computer to fail to display speed? Computer is not correctly slotted into the sensor holder. Casing is pushed over the spoke magnet. The distance between the spoke magnet and the sensor is too large. Bike computer contacts must be cleaned. Sensor cable has a break. Bike computer is defective. Operating instructions DE, GB, FR, NL, DK, ESP, IT, PL, CZ