A slight incline
To use a very British term, things were ‘rather poorly’ in the motorcycle trades as the ‘thirties decade dawned.
The Depression was biting ever harder, and Royal Enfield recorded a trading loss (of £2,000) for the first time in their history for the financial year 1930/31. At least the company managed to pay its shareholders a dividend (of 5%), which is something many other companies were unable to achieve. The company even continued to enter a factory team in the Isle of Man TT right up until 1935. Despite the gloom, Royal Enfield also pressed on with model improvements, and even completely new models, one being the 499cc Model J which had revised engine dimensions with a longer stroke to achieve a capacity of 499cc. There was even a four-valve single, the Model JF, of 488cc, reputedly capable of 110mph, which in 1932 became the first Royal Enfield to use the Bullet name, a model still in production today, which by 1934 would be available in 250cc, 350cc and 500cc form.
At the time, ‘slopers’ were all the rage, with models from BSA, Cotton/JAP, New Hudson, Zenith, Matchless, Dunelt, Excelsior, Ariel, AJS and Panther among the major manufacturers. So it was not entirely unexpected that Royal Enfield should have one as well, which they did with the 346cc side-valve Model F, the ohv version Model G, and the 488cc side-vale Model H and its ohv cousin the Model J. These engines were dry sump and carried the oil in a compartment in the front of the crankcase. The J continued the styling adopted in 1928 with saddle fuel tank, with small round rubber knee pads. For 1931, the Model J was redesigned as the J31 with a longer stroke of 99.25mm and a bore of 80mm to give 499cc. The H31 used the same