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LOT 748

1934 BSA 500cc Model J34-11 Registration no. 231 UXN Frame no. B11-934 Engine no. none (see text)

Sold for £23,000 inc. premium
Lot 748

1934 BSA 500cc Model J34-11
Registration no. 231 UXN Frame no. B11-934 Engine no. none (see text)

1934 BSA 500cc Model J34-11
Registration no. 231 UXN
Frame no. B11-934
Engine no. none (see text)

• Produced for only three years
• One of the rarest and most desirable of 1930s BSAs
• Fully restored by Robin James Engineering Services

"As I knew I would, I loved it immediately – the sound, the comfort, the look, it's all perfect, making the half-litre BSA V-twin really one of the most delightful machines of the 1930s." – James Robinson, testing '231 UXN' for The Classic Motorcycle, March 2017.

During the 1930s BSA concentrated on producing an extensive and varied range of dependable, well-made and competitively priced motorcycles. The majority of these were singles but for the sidecar market BSA offered the Model G 985cc sidevalve v-twin and, for the more sportingly inclined rider, a smaller overhead-valve v-twin, the 499cc Model J. Somewhat surprisingly, given its complexity, the newcomer had originally been developed for the War Office. Predictably, it was rejected by the latter, which tended to favour sidevalve singles for military use, and appeared for the first time in civilian guise in the 1934 range as the J34-11. Typed J35-12 the following year, it was joined by a 750cc version, the Y13, before ceasing production at the end of 1936 as the J12. Although the '500' had gone, the 750cc v-twin continued until the end of the 1938 season. Produced for only three years, the handsome Model J is today one of the rarest and most highly sought after of all 1930s BSAs.

This beautiful four-speed example was completely restored between 2005 and 2016 as close to factory specification as possible, the work being carried out by the highly respected Robin James Engineering Services (see file). Unfortunately, the crankcases were damaged beyond repair and had to be replaced. As luck would have it, RJES already had a timing-side crankcase half from a 750cc Model Y in stock, while a new drive-side crankcase half was cast and machined in house (hence no engine number stamped). Unfortunately, the original cases are not available.

Shortly after the restoration's completion, '231 UXN' was tested for The Classic Motorcycle by the magazine's editor, James Robinson (March 2017 edition, copy available). The machine also comes with a V5C document and BSA OC and VMCC dating certificates.

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