350cc - 500cc 

3T 1945-51, 349cc, ohv twin, 335lbs, 75mpg, 75mph

Basically a smaller version engine of the 5T in rigid frame and poor brakes.  This was the small light weight tourer. Plunger suspension came in 1947 but is not easy to work with. Later replaced by the T3A in 1957

3TA Twenty-One 1957-69, 348cc, ohv twin, 360lb, 70mpg, 80mph

Unit construction twin with Bathtub rear end and pigeon catcher front guard. Also called the 21 (Celebrating 21 years of Triumph engineering), this was the first unit-construction Triumph. Handling was not particularly good, which when combined with poor brakes and ignition problems do not make it a desirable bike.

T90 Tiger 90 1963-68, 349cc, ohv twin, 340lbs, 70mpg, 90mph

Sports version of the 3TA motor in a new single down-tube frame. The cut down Bathtub rear end was dumped in 1964 in favour of the classic Triumph look. There was an improved frame in 1967 and decent forks in 1968.

Bandit 1970-72, 349cc, OHC twin, 345lb, Prototype

Announced at the last Major Motor show, this twin was state of the art alloy engineering designed by Bert Hopwood. Carrying many of the now established Japanese components, such as electric start, indicators, twin overhead cams, it is a shame that it never made the production line, as tests proved it to be a good bike.

5T Speed Twin 1937-58, 490cc, ohv twin, 375lb, 65mpg, 90mph

Famous Speed Twin which was ahead of it's time in many ways, but was a handful when taking corners fast. Plagued with oil leaks, vibration and noisy rattles as well as poor handling the engine was just taken from the pre-war model, original 1937. Adopted the famous nacelle in 1949.The rear sprung hub is complex and lacks spare parts,1955 saw the swinging arm frame. 

T100 Tiger 100 1939-57, 490cc, ohv twin, 370lb, 60mpg, 100mph

Pre-war model with telescopic front forks added in 1945, this was the sports version of the 5T. The all alloy engine is rather noisy. The early models had rigid rear end or sprung hub, which were eventually replaced by swinging arm in 1955, but this did not radically improve it's handling. 

TR5 Trophy 1949-58, 490cc, ohv twin, 370lb, 60mpg, 100mph

An off road version of the Speed Twin with alloy top end and a shorter frame. There was a "C" model which stands for competition. Triumph made several models in this specification, which were export models aimed at the USA for off-road riding. Usually it entailed, high level exhaust pipes, high wide handle bars, small headlight, non-valanced mudguards, off-road tyres, energy-transfer ignition, lowered gearing, smaller petrol tank and stiffened frame. 

5TA Speed Twin 1959-60, 490cc, ohv twin, 375lb, 65mpg, 90mph

Basically an updated Speed Twin which retained the same colour scheme of Amaranth red.

T100A/SS/C, 1960-71, 499cc, ohv twin, 340lbs, 70mpg,100mph

Unit construction Tiger based on the 5TA fitted with ‘bathtub’ rear enclosure which was not popular at the time. 1961 saw the T100SS with the half bathtub. Improvements came in 1967 with a better frame and in 1969 with TLS drum front brake. The 1970 T100C suffered from poor build quality but had nice chassis and single carb giving performance and economy.

T100T/R Daytona 1967-73, 499cc, ohv twin, 340lbs, 65mpg, 110mph

Twin carb version the Daytona was a nice looking bike but not a great improvement on power. 1968 T100C had twin mid-level exhaust pipes running down the left-hand side. 1970 came the T100R not  a great improvement .

TR5MX Avenger 1973-74, 499cc, ohv single, 340lbs, 60mpg, 85mph

Really a BSA B50MX with Twin silencers from one exhaust. 

TR5T Adventurer 1973-74, 490cc, ohv twin, 330lb, 50mpg, 80mph

Triumph twin engine in a BSA street scrambler frame. Rare. Pleasantly vibratory with rugged good looks.

TRW 1948-65, 500cc, sv twin, 375lb, 65mpg, 70mph

Old side-valve brute that was popular with the military. Suffered from poor fuel economy. Many parts borrowed from the Trophy trials range.