The camshaft was geared directly from the crankshaft with skew gears driving the oil pump and the contact breaker assembly mounted behind the cylinder via a shaft . The alternator was to the left and the primary drive was via a duplex chain to a multi plate clutch.
22.
Tellingly, the author found that whilst Triumph'was well able to design and build a model to match contemporary Japanese designs in engine performance, and to out-handle them on the road', the contact breaker points assembly required replacing during the ride.
23.
For example, the position of the contact breaker points relative to the engine angle can be changed a small amount dynamically, allowing the ignition timing to be automatically advanced with increasing revolutions per minute ( RPM ) or increased manifold vacuum, giving better efficiency and performance.
24.
Two episodes of 1970s police drama " The Sweeney " included scenes filmed on Blyth Road, Hayes : " Contact Breaker " ( Series 1, Episode 12; broadcast 20 March 1975 ), and " Faces " ( Series 2, Episode 2; broadcast 8 September 1975 ).
25.
Instead, the frame was purpose-built to properly hold the engine, and the Quadrant motorcycles also pioneered a suction inlet valve, hand oil pump and direct drive, contact breaker ignition replacing trembler ignition in 1902, as well as a spray carburetor in 1904 and magneto ignition in 1907.
26.
The bike proved to need careful maintenance, being prone to oil leaks, electrical faults, gearbox problems, valve-gear failures, a weak big-end, and clutch adjustment problems . Initially, the contact breaker housing protruded at the rear of the cylinder above the gearbox, but was later relocated to the right-side crankcase, accessed via a circular plate.
27.
Soon, however, even these contact breaker points were replaced by an angular sensor of some kind-either optical, where a vaned rotor breaks a light beam, or more commonly using a Hall effect sensor, which responds to a rotating magnet mounted on the distributor shaft . The sensor output is shaped and processed by suitable circuitry, then used to trigger a switching device such as a thyristor, which switches a large current through the coil.
