The triple-cylinder engine, as applied to motorcycles, provides an engine that can be inherently balanced. If you listen to a triple-cylinder motorcycle, such as a Triumph Trident or BMW K75, it sounds smoothly balanced for good reason. You will also coincidently notice that an engine with a multiple of three cylinders sounds smooth by comparison with a V8 for example. An inline-6, V6 or V12 are smooth sounding because of the relative ease with which such engines can be made balanced. So if you’re looking for a motorcycle that won’t rattle your bones, then the triples are bikes you should probably consider.
Amongst the first of the production triple-cylinder motorcycles was the Triumph Trident, which was in production from 1968-1975, and its badge-engineered sibling the BSA Rocket 3. The Triumph Trident was the last motorcycle developed and produced by Triumph Engineering at their original Meridan factory in Britain’s West Midlands. The Trident, and its BSA Rocket 3 sibling, featured an air-cooled in-line 740cc transverse triple-cylinder engine producing 58bhp at a brisk 7500rpm. The engine was mated in a unit construction assembly with the four speed gearbox and drove the rear wheel by chain drive.