intended to replace the AG Three speed 'Dyno-Three' Dynohub. Both the SB and SG would have used a modified set of SW internals with a shortened planet cage to facilitate the additional functionality on the left side of the hub. Technical drawings for both the SB and SG exist and both appeared in catalogues, however there is no evidence that either hub went into production and the AB/ABC and AG re-appeared alongside the AW in 1958. The AW had been built under license by The Hercules Cycle and Motor Company as the A type in the 1940s and the B type in the 1950s (there is no functional difference and the letter merely denotes the decade). Hercules put their name on SW hubs too, though these are far less common than Sturmey-Archer branded SWs. After the failure of the SW in the market and the re-commitment to the AW, Sturmey-Archer continued to widely license the design, with fully interchangeable clones of the AW eventually being made under labels including J.C. Higgins, Sears, Austro-Daimler, Brompton, Brampton, SunTour, and others. S2 'Automatic' In 1966 Sturmey-Archer launched a new two-speed hub with a backpedal shifting action similar to the Fichtel and Sachs 'Torpedo Zwei Gang Duomatic'. The S2 – Sturmey-Archer's first 2-speed hub since the demise of the T series in 1941 and the last two speed they would make in the UK – featured a direct drive and a 28.6% gear reduction. While its lack of need for a gear cable might have led to the S2 being a popular choice for small wheeled and folding bicycles, the nature of the gears meant that a small wheeled bicycle would struggle to obtain acceptably high gearing within the constraints of a) the size of its wheels, b) the minimum size of sprocket which could be fitted and, c) the maximum size of chainwheel which could be obtained. For these reasons, it was commercially unsuccessful. Shifting the S2's gears was achieved by reversing the pedal action such that the sprocket and driver rotated 1/4 turn anti-clockwise relative to the axle (the amount of pedal movement required for this is gearing dependent). The up-shift and down-shift process is the same, with the hub toggling between gears; there is a consequent risk of overshooting the desired gear. The S2 has no equivalent to the sliding clutch seen in 3- and 4-speed Sturmey-Archer hub designs, there is