The fastest time to cycle 100 km on a tandem bicycle (mixed) is 3 hours 6 minutes 51 seconds, achieved by Lady JB Owen and Peter Giesin on the certified Moffat–Mosca road course along Colorado Highway 17, Colorado, USA, on 26 September 2026. The pair maintained an average speed of 32.11 km/h (19.95 mph) on a steel Co-Motion Java adventure-touring tandem without aerodynamic equipment, riding through dense fog, freezing moisture and rising winds. The record was officiated and ratified by the World UltraCycling Association (WUCA).