BSA Royal Star
Encyclopedia
The BSA Royal Star is a British
motorcycle
that was a radical new design for BSA
that paved the way for a whole range of very successful unit construction
twins. As well as giving a clean look to the engine, with the pushrod passages part of the cylinder block casting, unit construction reduced the number of places oil could leak from.
recognised the need for a completely new look that built on the best features of the A10's but would succeed in the potentially lucrative but competitive US market. Working with Chief Development Engineer Bert Perrigo they developed the unit construction Star twins. Launched in 1962 the as the 500cc BSA Star and later the more sporty Royal Star The model was widely exported to the USA and Australia
as well as becoming a top seller in the UK in the early 1960s.
The Royal Star had a relatively small single Amal monobloc carburettor, and later Concentric carburettor, but in 1964 new pistons and a new gearbox improved performance. The machine had a top speed of about 90 mph and was relatively free of vibration. Sharing common engine and cycle parts with the larger BSA A65 Star
650 twin, it was an over-engineered machine and proved very robust. The only major fault with the engine design was a plain crankshaft bearing on the timing side which, when worn, would cause a drop in oil pressure. In 1965, BSA addressed the bearing issues with a roller bearing on the drive side, as it had been on the pre-unit engines, with an improved bronze bushing on the other end.
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
motorcycle
Motorcycle
A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most...
that was a radical new design for BSA
Birmingham Small Arms Company
This article is not about Gamo subsidiary BSA Guns Limited of Armoury Road, Small Heath, Birmingham B11 2PP or BSA Company or its successors....
that paved the way for a whole range of very successful unit construction
Unit construction
Unit construction is a term used to describe the design of larger motorcycles where the engine and gearbox components share a single casing. The term is sometimes applied to the design of automobile engines and was often loosely applied to motorcycles with rather different internal layouts such as...
twins. As well as giving a clean look to the engine, with the pushrod passages part of the cylinder block casting, unit construction reduced the number of places oil could leak from.
Development
Bob Fearon, Managing Director and General Manager of BSABirmingham Small Arms Company
This article is not about Gamo subsidiary BSA Guns Limited of Armoury Road, Small Heath, Birmingham B11 2PP or BSA Company or its successors....
recognised the need for a completely new look that built on the best features of the A10's but would succeed in the potentially lucrative but competitive US market. Working with Chief Development Engineer Bert Perrigo they developed the unit construction Star twins. Launched in 1962 the as the 500cc BSA Star and later the more sporty Royal Star The model was widely exported to the USA and Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
as well as becoming a top seller in the UK in the early 1960s.
The Royal Star had a relatively small single Amal monobloc carburettor, and later Concentric carburettor, but in 1964 new pistons and a new gearbox improved performance. The machine had a top speed of about 90 mph and was relatively free of vibration. Sharing common engine and cycle parts with the larger BSA A65 Star
BSA A65 Star
The BSA A65 Star was a Birmingham Small Arms Company motorcycle aimed at the US market for unit construction twins. As well as giving a clean look to the engine, with the pushrod passages part of the cylinder block casting, unit construction reduced the number of places oil could leak from...
650 twin, it was an over-engineered machine and proved very robust. The only major fault with the engine design was a plain crankshaft bearing on the timing side which, when worn, would cause a drop in oil pressure. In 1965, BSA addressed the bearing issues with a roller bearing on the drive side, as it had been on the pre-unit engines, with an improved bronze bushing on the other end.