Auto Union, DKW's parent company, was re-founded in Ingolstadt in the American occupation zone in Germany, and resumed RT 125 production in 1949.

The Zschopau factory later became MZ[citation needed] In 1955 Yamaha launched its YA-1, which was its first production motorcycle.

It was designed as a mirror image of the RT 125, so that the gearchange was on the right side, in conformity with other British motorcycles of the period,[2] and with measurements changed from metric to inches.

At first the D1 was offered in only one colour, Mist Green, with an ivory panel painted on each side of the fuel tank.

[4] In subsequent years BSA developed the Bantam with battery electrics; damped front suspension; rear suspension with plungers, and then with a swinging arm; larger engines; a steel silencer that could be dismantled for cleaning; and a four-speed gearbox.

Models from 1959 onward have a swinging arm frame that bears little relation to the rigid, plunger and initial swinging-arm versions.

Ignition is of two types: a Lucas battery-powered coil in earlier machines, or a Wipac magneto.

Windings give power either directly to the lights (with a dry cell for when the engine was stopped) or via a rectifier to a lead-acid battery.

On later D1s BSA fitted a more conventional cylindrical silencer, from which the baffles can easily be removed for cleaning.

High-level exhausts were made for the trials and off-road models, in which the only electrics are the magneto-powered ignition.

The D175 was marketed as the B175 as BSA struggled against imports in the late 60s to its closure in 1972 (the larger capacity "B" series having helped make them the largest motorcycle manufacturer in the world).

The engine size shown is nominal, British motorcycles were made 1 or 3 cc smaller than their tax bracket maximum to allow for re-bores and wear.

BSA introduced optional plunger rear suspension in 1950,[5] and stopped making the rigid-framed version in 1956.

The AC system used a small dry "torch" cell battery to illuminate the forward-facing "pilot" bulb within the headlamp shell.

The DC system included a lead acid battery and operated in a conventional manner.

[citation needed] This model is identical to the standard D1, except for a black tank with chromium strip on top and cream side panels; black frame and mudguards; chromium plated wheel-rims; polished primary chain cover; and crash bars; legshields; and larger luggage rack.

The model was available by special order from 1949 to 1953 in the overseas market, primarily in Canada, US, Australia, but not in the UK.

BSA finished all D3s in pastel grey, with ivory panels on either side of the fuel tank.

In the same year BSA introduced "sapphire blue" as a colour option, alongside black or royal red.

The Bushman is the off-road version, with a plate under the engine to protect the crankcase; high-level exhaust; 19-inch wheels; 58-tooth rear sprocket; increased ground clearance; and a unique colour scheme of orange and white.

BSA discontinued the Silver Bantam, and offered only three models: Supreme, Sports, and Bushman.

BSA revised the fixing on crankshaft compression disc plates to cure the problem with the D14/4.

[19] This final model was produced from 1969 to 1971, finished in metallic red and blue or plain black, all with white painted linings on the fuel tank, mudguards and side panels like the D14/4.

The right hand side panel covers an efficient large air filter that feeds the Amal 626 Concentric carburettor via a rubber hose.

[citation needed] The off-road Bushman version was available as an export model, for Africa and Australia in particular, but 300 were sold in the UK.

Bushman models proper were equipped with lights, high-level exhaust, side stand, and dualseat.

There was a Pastoral model for commercial farming that had single saddle and carrier rack instead of a dualseat.

Even by the mid-1970s the Bushman models were sought after by collectors and they are even more so today an amazing 49 years after BSA produced the last ones in 1971.