Sturmey-Archer was a manufacturing company originally from Nottingham, England. It primarily produced bicycle hub gears, brakes and a great many other sundry bicycle components, most prominently during their heyday as a subsidiary of the Raleigh Bicycle Company. In the past, it also manufactured motorcycle hubs, gearboxes and engines. The company was founded in 1902 by Henry Sturmey and James Archer under the guidance of Frank Bowden, the primary owner of Raleigh. In 2000, the assets and trademarks of Sturmey-Archer were sold to Sun Race of Taiwan which was renamed Sun Race Sturmey-Archer Inc. and production moved to Taiwan. Products All Sturmey-Archer gear hubs use epicyclic (planetary) geartrains of varying complexity. The AW is the simplest, using one set of planetary gears with four planets. The AM uses three compound planets with differently sized cogs machined from a common shaft to engage the gear ring and sun gear separately, while the close-ratio three-speeds, and hubs with four or more speeds, use multiple planetary geartrains. Depending on the specific hub these may be in series with each other, or with one or the other set being selectable at any given time by locking a particular sun gear to the axle. 'K' family hub gears In 1921, the K hub was introduced as an updated and improved version of the X, later FX hub (following the introduction of fine axle threading) - it is the Model X which was manufactured under license by BSA as their 3 speed hub until 1956. The new K model three speed had ratios of 75%, 100%, and 133%, the same as the later AW, however its internal workings were substantially different. Most notable was the 6-prong ramped sliding clutch which was mounted between springs, this gave the advantage of lateral movement being possible without shifter movement and allowed gears to be pre-selected while pedalling, the ratio would change when pedal force was relaxed, freeing the mechanism to slide into the new gear and under spring pressure. The ramped clutch dogs and sprung mount also permitted the K hub to be without a neutral position between the 'Normal' direct drive gear, and the 'High' overdrive gear, both the SW and AW (until the mid 1990s) have this neutral position. The gear ring dogs would ratchet around the clutch using the ramps and springs if the hub was trying to engage Normal and High gear at the same time,