Royal Enfield WD / RE The Royal Enfield WD / RE known as the " Flying Flea " was a lightweight British motorcycle developed by Royal Enfield for the British War Office ( the WD came from War Department ) as a means of transport for that could be dropped by parachute or carried in gliders , to quickly carry messages and signals between airborne and assault troops where radio communications were not in place . Development . The best known Royal Enfield produced for the Second World War was the WD / RE 125 cc which was known as the " Flying Flea " and designed to be dropped by parachute with airborne troops . After the German authorities stopped the Dutch franchisee of the DKW RT100 motorcycle from receiving any more supplies in 1938 , preferring a non - Jewish company , Royal Enfield was contacted by the displaced importer about producing a similar motorcycle . Royal Enfield ' s version of the bike was produced by Ted Pardoe , who expanded the engine . Two prototypes under the name ' Royal Baby ' were shown at Rotterdam in April 1939 . Using a less sophisticated but increased - capacity two - stroke engine in the same frame , a few of these RE motorcycles were made before the outbreak of the Second World War . As with other British motorcycle manufacturers , the Royal Enfield factory production was turned over to the war effort . Military motorcycles included the Royal Enfield WD / C 350 cc sidevalve , the Royal Enfield WD / D 250 cc sidevalve and the Royal Enfield WD / L 570 cc . In early 1942 , the War Office ordered twenty WD / RE motorcycles from Royal Enfield for testing . Based on their 1939 civilian pre - war design , the prototype had a right hand brake and was fitted with an Amal carburettor and had a low - mounted toolbox . The trials went well and led to some modifications , including fitting a twin - box exhaust system to help silence the noisy two stroke engine , a Villiers carburettor ( indicated by a ' V ' on the engine ) , raising the toolbox and fitting a folding kick - start , footrests and even folding handlebars , so that it could be packed into the smallest possible space . A Miller lighting system was added , together with a sealed vent on the fuel filler to prevent spillage when the motorcycle was packed in a drop carrier . The foot brake was also relocated to the left side . The reason the War Office wanted such a lightweight motorcycle was to establish communications between troops that had been dropped by parachute and the front line forces , who could be some distance away or out of radio contact . The problem was how to make sure that the Enfield landed without too much damage . In the summer of 1942 experimentation therefore began to develop a protective cradle that would go right round the motorcycle . A number of different versions were tested by dropping them from the bomb racks of aircraft such as the Halifax and Lancaster bombers . As well as surviving the drop , the cradles also had to be easy to remove on landing . The prototypes met neither requirement as they were too light and bent the wheels on impact but eventually a design was developed that worked with heavier tubing and increased bracing and in December 1942 , went into production at the Enfield ' s Calton Hill factory in Edinburgh . The first significant orders for the Royal Enfield WD / RE were consequently placed during early 1943 , but after all the planning and preparation only a few were actually dropped into the battle zone by parachute , as it was decided to load them into troop carrying gliders four at a time without the protective frames , and secured by a special harness instead . A number of Royal Enfield WD / RE motorcycles were also used for beach landings during 1943 and 1944 , and were carried inside landing craft for communication between the beaches and the nearest front line forces . Early production bikes were fitted with a small taillight and military - issue headlamp fixtures to help hide the bikes and riders from enemy aircraft . The Flying Flea could run on any fuel and its light weight meant that soldiers could carry their bikes over otherwise impassable terrain . Post war . There was a huge demand for cheap and reliable transport after the war so any surviving models which were disposed of as war surplus were stripped down and repainted for civilian use . Most of this work was carried out at Enfield ' s Bradford - on - Avon works in Wiltshire . A few military Royal Enfield WD / RE motorcycles remained in limited service use until the end of the 1940s . Royal Enfield also produced a civilian version of the bike in the post war years , the RE125 , through 1950 , when a foot - operated gear change lever was added and the front forks were modified to a telescopic style with internal spring dampening . In 1951 the RE2 was introduced with a redesigned frame and engine . The line ended in 1953 with the introduction of the Royal Enfield Ensign .