2891 YD - Triumph 549 / 550cc. Model ‘H’ side valve - 1919 England GB.

The model H is announced late in 1914 as a logical development of the famous veteran “ Trusty”.
But it isn’t just a 1914 model with a countershaft gearbox: the engine differs from the veteran engine in various ways.
It has a single cam wheel with 2 cams instead of separate camwheels for the inlet and exhaust valve.
The casting for the cylinder is entirely new, the valve head diameter is enlarged by ¼ inch and the valves are spaced further apart.
A great improvement over the 1914 style 3-speed hub is the Sturmey Archer countershaft gearbox.
The primary chain drive is enclosed by a neat aluminium cover; secondary drive is by belt.
The new model becomes available in February 1915 and most of the production goes to the British Armed forces; in 1918 the army has just over 17,000 Model H’s. It is not until 1919 that the Model H is again available, in very small numbers, for the civilian market and many ex- army machines are sold off at surplus sales at Slough.
According to available dating information the frame numbers for 1919 civilian machines started with # 301978 so the machine on offer would have been such a civilian model.
The OTO engine number suffix refers to September, 1919 as production month.
For detailed information on the Model “H” consult Peter Cornelius’ “The Facts” booklet, surf to http://users.actrix.co.nz/cornelius/Triumph/
This trusty H is an older restoration and a good runner.