BOOK OF THE BSA SUNBEAM & TRIUMPH TIGRESS 175cc & 250cc SCOOTERS 1959 TO 1965 - Paperback

by J. Thorpe (Author), Floyd Clymer (Contribution by), Velocepress (Producer)

110 pages, and 70 illustrations and charts, size 5.5x8.5 inches. This publication covers all three variations of the BSA Sunbeam and Triumph Tigress 175cc two-stroke and the 250cc four-stroke and electric start models manufactured from 1959 to 1965. Originally published under the same title in 1967 as a corrected version of the previous 1963 edition by J. Thorpe, this book is one of The Motorcyclist's Library series published in the USA by Floyd Clymer by arrangement with the original publishers, Pitman Ltd. of London, England.

MANUALS & TECHNICAL PUBLICATIONS: Neither BSA nor Triumph ever published a workshop manual for these models, however, those owners interested in acquiring additional technical information are directed to our publication ISBN 9781588502537 which includes a compilation of the 3 major factory manuals identified below. The combination of these three publications provides the most comprehensive maintenance and repair information that was ever made available from the manufacturer.

Maintenance, repair and service information was issued under both the BSA and Triumph name. However, as the machines were identical in all aspects, any technical documentation can be applied to either manufacturer without hesitation.

SERVICE SHEETS: Beginning in December 1959, both BSA and Triumph began publishing repair, overhaul and technical information in the form of individual (dealer only) 'Service Sheets'. It should be noted that it was never intended that these service sheets would be distributed to the general public. However, they were eventually combined into a single publication and released under both the BSA and Triumph names, the contents being identical in either case.

INSTRUCTION MANUAL: Both BSA and Triumph published an identical 'Instruction Manual' the only difference being the name on the front cover. These publications were somewhat more detailed than typical 'owner's manuals' as they included overhaul information in addition to general maintenance and adjustments. As these instruction manuals were included with each new scooter purchased, there were a number of 'editions' published during the lifetime of the model, however, the contents remained basically unchanged. When combined with the 'Service Sheets' they are a reasonable substitute for a workshop manual.

PARTS (or) SPARES MANUAL: The parts manuals are also identical and include exploded component diagrams that are extremely helpful in the rebuilding or restoration process.

DESIGN & GENERAL SPECIFICATIONS: Designed by Edward Turner (Triumph) and sold under both BSA and Triumph brand names to take advantage of established distribution networks, this badge engineering was one of the last uses of the Sunbeam name. The differences between the BSA Sunbeam and Triumph Tigress were entirely cosmetic - the former in polychromatic green paint, also two-tone red and cream, with a BSA badge; the latter in a shell blue or mimosa and ivory (two-tone) with a Triumph badge.

Introduced in late 1959, the scooter was available with a 250cc four-stroke twin (10 hp), or 175 cc two-stroke single cylinder engine (7.5 hp). Both engines were forced-air-cooled. The two-stroke was a development of the BSA Bantam engine but the four-stroke was a completely new parallel-twin with a gear drive to the gearbox. The contact-breaker fed two separate ignition coils, each of which connected directly to its own spark plug without the need for a distributor. Drive to the rear wheel was by a fully enclosed chain in an oil bath. Both versions had four, foot-operated gears. Some of the 250 twins were fitted with an electric starter and a 12 volt (not 6 volt) electrical system, they were identified as either B2S (Sunbeam) or TW2S (Triumph). The 250cc four-stroke model was discontinued in 1964 and the 175cc two-stroke model in 1965.