Triumph Speedtwin 1957
The era of the 'BathTub' begins.
In 1957, Triumph produced its first all unit construction machine in the 'C' Range - the 350cc 3TA, otherwise known as the Twenty-One, due to it being 21 cubic inches capacity and the 21st Anniversary of 'Triumph Engineering Co. Ltd.'
Amongst all the new features, it sported an enclosed rear end, dubbed the 'BathTub'. Possibly the first Police Specification 3TA was supplied to the Bucks Constabulary in November 1958.
In 1959 it got a big brother in the form of the 500cc 5TA - basically the same as a 3TA, but more powerful and police took their first delivery of the model in that year.
1959 was also the year that the Bonneville was introduced and in the following year a sports version of the 5TA minus bathub was introduced - the T100 - which also saw police service.
In 1960 a total of 6 3TA's and 42 5TA's were built for the police. In 1961, 18 5TA's were built. Police sales of the 3TA & 5TA in 1963 were 47 and 104 respectively and in 1964 this was 41 & 28. In 1965 it was 95 & 11 plus 21 T100's.
1966 was the last year of 3TA & 5TA production, with police sales of 298 & 255.
Police machines often show specifications and parts that differ from the other production models such as side panels without switches, unusual seats, early type mudguards, switchgear and other parts that are generally unobtainable as spares and not usually illustrated in the parts books.