Currently only rides that last less than 24 hours count toward the Gran Fondo Challenge. There are several events in Ultra Endurance cycling that can last longer than 24 hours - for example the Unbound Gravel XL (350 mi / 36-hour time limit) and the Gravel Worlds Long Voyage (300 mi / 30 hr. limit). I was very disappointed when my finish at Gravel Worlds last year did not count towards the Gran Fondo Challenge. Can the 24-hour limit be removed?
