RealClassic ROYAL ROYAL ENFI0LD 250S
These interesting, slightly quirky machines appeared for the 1957 season, pipping BSA's C15 to the post and probably making BSA sweat a bit. Worse, Royal Enfield's new offering must have appeared to be light years ahead of what the largest British manufacturer had to offer at that time. Initially boasting some 13bhp, Enfield's early machines had no sporting pretensions but were a major advancement over the rarely-seen pre-unit Clipper models which preceded them.
Compact and light by comparison, the unit construction 250s were some 30% more powerful. The 17“ wheels started out with 6” full-width hubs and sis stoppers, a cush drive sprocket / brake drum assembly and full rear chain enclosure. A one-piece crank used an alloy conrod with a split big end. These early machines sported a cast iron cylinder head and barrel.
Many minor details changed during the production run, most notably a 7" sis full-width front hub and alloy cylinder heads. There were also changes to camshafts, crankshafts, compression ratios, port and carburettor sizes; 375,376 and 389 Monoblocs were all used on different models and some of the last GT machines sported 900 series Mk1 Concentrics. Other mods were made to the kickstart shaft diameter and the shape / style of mudguards, fuel
