On the outbreak of the First World War the cyclist battalions were employed on Coastal Defences in the United Kingdom. Their role was considered to be so important that, initially, none of them were sent overseas. In 1915, the Army Cyclist Corps was founded to encompass these battalions. They were not deployed as organised combat formations, when cyclists were employed in combat, in conditions of trench warfare they were generally found to be ineffective. The bicycle was used for reconnaissance and communications work, being lighter, quieter, and logistically much easier to support than horses.
The 6th (Cyclist) Battalion, Royal Sussex Regiment was disbanded in December 1919 and not re-formed