Here Is Some Information On The 650cc - 750cc Bikes
6T Thunderbird 1950-66, 649cc, ohv twin, 400lb, 60mpg, 95mph
Soft and smooth tourer with customary Triumph characteristics, which had the new swinging arm frame and the Pre-unit Triumph twin. The sports version was the Tiger 110, which was introduced in 1954 and had better brakes. 1960 saw the bathtub model introduced.
T110 Tiger 110 1954-61, 649cc, ohv twin, 400lbs, 60mpg, 115mph
This Tiger had the new swinging arm frame. Basically a sports model of the 6T Thunderbird. 1960 saw the bathtub model introduced.
TR6 Tiger 650 1961-73, 649cc, ohv twin, 400lb, 55mpg, 105mph
Single carb version of a Bonneville which was the replacement for the Thunderbird. The engine prefix TR6P denotes an ex-police bike. 1963 saw the unit-construction model.1972 saw the 5 speed gearbox and 1973 front disc brakes.
T120 Bonneville 1959-62, 649cc, ohv twin, 400lb, 50mpg, 110mph
Fast super-sports pre-unit 650 with twin carbs. Noisy, with vibration and poor handling at speed. An excellent bike which gained it's reputation from the Land Speed Record.
T120R/V Bonneville 1963-74, 649cc, ohv twin, 410lb, 50mpg, 115mph
The unit-construction Bonneville has better handling than the earlier models and especially after 1971 with the oil-bearing frame, better forks and conical hub brakes. Good ones are relatively smooth, oil tight and quiet. 1966-70 bikes fetch the best prices. 1972 saw the 5 speed gearbox and 1973 front disc brakes.
T140V Bonneville 1973-88, 744cc, ohv twin, 440lb, 50mpg, 110mph
Bigger version of the 650, which lacked development and was consequently ruined by excessive vibration. Limited editions: 1977 Silver Jubilee, 1979 T140D with cast wheels, 1980 Executive with fairing and top-box, 1981 Royal Wedding.
TR7RV Tiger 750 1973-83, 744cc, ohv twin, 430lb, 48mpg, 105mph
Single carb version of the Bonneville. Similar performance but with less charisma than the T140. Easier to tune and run making this a more desirable option.
TSS 1982-83, 744cc, ohv twin, 420lb, 45mpg, 120mph
The T140 engine got a new eight valve head giving a little bit more performance, which came with an optional anti-vibration frame. Unfortunately, it’s reliability suffered because of the four valve per cylinder design which led to overheating. A Bonneville with an 8 valve head giving a little more performance by trading off reliability. The TSX was a custom version with cast wheels.
T150 Trident 1970-75, 740cc, ohv triple, 503lb, 37mpg, 120mph
The Triumph upright triple with 5 speed box and heavy frame. 1972 the disc front brake replaced the conical hub drum which for a bike of this capacity should have been standard from the start. In 1973 there was also a Hurricane version the X75.
Final version of the Trident, which had more reliable engine based on the BSA inclined Rocket with electric start, rear disc brake and left foot gear-change. Fast with excellent handling, but performance suffered due to emission controls.