1928 HUMBER 3.49hp OHC

Here's a rare bird; Humber was one of the original motorcycle makers in Britain - according to 'The Autocar' of June 6, 1896, ' the first practical motorcycle made in this country was completed last week when Humber & Co finished a bicycle fitted with a Pennington two-horsepower motor...'.

Humber started life in 1868 making bicycles, and branched out to making cars about the same times as they added an engine to one of their bicycle frames. By around 1903 the cars especially became very successful, with motorcycle and bicycle production developing alongside. The factory backed a racing team in the Isle of Man TT in 1911, and won the Junior TT (PJ Evans aboard) with their 350cc inlet-over-exhaust-valve v-twin. The factory also made sporting flat-twins (a la Douglas), and a machine which they copied from no-one; a 3 cylinder flat triple! One cylinder in front (78 x 78mm), two at the back (58 x 78mm), nominally 6hp, but which works out to 785cc... I'll try to find a photo!

The success of the Humber cars and their excellent construction became the undoing of the motorcycle branch, as the Rootes Group (which had already absorbed Sunbeam, Hillman, Singer, Commer, and Talbot cars) took over the factory in 1930. Rootes had no interest in motorcycles, and rather than selling off this side of the business (it was, after all, the worst year of the Depression), they 'hauled down the motorcycle flag'.

This 3.49hp ohc machine (no catchy name like 'Lark' or even 'KSS') therefore represents the pinnacle of 34 years of motorcycle production, and was the top of their line, 'a very refined and sporting mount', according to 'The Humber Story' (Demaus & Tarring, 1989).

It's a very interesting little overhead-camshaft engine of their own make, with and adjustable oil feed directly to the cams via an oil pump on the cambox, although the engine lubrication is still total-loss. In general layout they certainly took their cues from the best, as it looks very much like a Velo K series, and even more closely resembles a racing Koehler-Escoffier 500cc ohc machine, which also has a total loss system, although not the oil pump directly on the cambox. The cambox itself shares the same rocker mechanism with the unfairly maligned Walter Moore Norton CS1 of 1927-29, in that the rockers exit the SIDE of the casting (see drive side detail photo), and don't move up and down through a leaky slot one either end of the cambox. It's so much easier to add an oil seal to a rocker shaft as on this machine, than try to seal a 1.5" long open slot....look at the back of any Manx or my mkIV KTT after a hard ride, and you'll know immediately what I'm talking about.

The rest of the machine is typical of the late Vintage period; bought-in forks (Brampton), gearbox (Albion), wheels (Webb or Enfield hubs), carb (Amac), magneto (ML), etc. The factory would have of course made their own frames, and probably petrol tanks, as they must have had sheet metal pressing capacity for their cars...
Ohc machines are very rare in the Vintage period, and a motorcycle of such limited production like this one is an especially unusual discovery.