Reliability trials were endurance events that took place on public roads. Competitors covered a fixed distance in a set time, stopping at a series of checkpoints to complete tasks which tested their riding skills.
Examples of local reliability trials included a 125 mile course beginning and ending at the Diamond, Ballymoney and taking the competitors via Coleraine, Downhill, Magilligan, Mountain Brae, Limavady, Dungiven, Maghera, Kilrea, Rasharkin, Glarryford, Clough, Newtowncrumlin, Orra Lodge, Glendun, Ballycastle, Glenshesk, Armoy (which incorporated a notorious water splash!) and back to Ballymoney. Reliability trials were usually open to all classes of motorcycles and cars. One of the largest trials witnessed in Ballymoney was staged in 1924 by the Ulster Motor Cycle Club when competitors on over 100 bikes, many with sidecars, passed through the town.