In the early days engines from De Dion powered their tricycles and quadricycles were followed by a Minerva powered motorize bicycle. By 1904 the firm was concentrating on car production, resuming motorcycle manufacture around 1910 with a Swiss 2¼hp v-twin Moto Sacoche powered lightweight. A 2¾hp version with two-speed gear and all-chain drive followed in 1911 (model 150 and 160), both with Moto Sacoche 344c v-twin engines These machines were equipped with the famous Enfield two-speed gear, involving twin primary chains and shifting between the two. In the rear wheel hub a rubber cush drive was fitted to take the punch out of the chaindrive. This feature was to be incorporated into all Royal Enfields until the very end.

The famous JAP engined sidecar outfit joined the range for 1912 and was specially designed to be used as a strong sidecar puller. This model 180 has a 770cc 6hp v-twin engine and the before mentioned two-speed gears that could not be called a gear-box, because it shifted between the two primary chains. In a time that a lot of motorcycles did not have a clutch or gears, this was a big selling point. You could easy ride away from a stand still and didn't have to push the bike to get on your way. In the 1914 Junior TT eight out of nine Royal Enfield twins finished, with a very creditable five in the first twenty places. The Royal Enfield 2-gears were also used in bikes from other manufacturers, i.e. the French Clement.

Directly after the Great War Enfield marketed two successful models: the light 2¼hp 224cc two stroke and the V-twin sidecar machine. The V-twins were again powered by a 6hp or even 8hp JAP engines, for some years 965cc Vickers engines were used for the 8hp models. The engine drives like the 1913 model through a two speed countershaft assembly which is effectively two clutches that operate when the gear lever is pushed forwards and backwards to engaged the first or second primary chain. The bike has a hand start, which is cranked from the right hand side of the bike.

The factory decided to start producing its own V-twin engine from the 1925 season. This time a 'normal' 3 (for model 180) and 4 (for model 182)speed gear-box with hand gear change was used. The 976cc v-twin model was sold in two types, the model 180 for the touring version and the model 182 for the sports version with lower handlebars. The 1928 range was the first year of the saddle tank models. A special feature of this model is that both brakes are operated by foot pedals. The max power output is about 27HP; the bike also features full Lucas electrics. From 1930 onwards the model destignation number 180 was changed in a letter model code K.