[retro900]

how many generations of the traditional triumph twin?
do they have names at all? (like hd has knuckle,pan, etc.)

 

[Mecchanica]

Early Speed Twins, with six bolt cylinder base
Speed Twins, 500cc, rigid frame, eight bolt cylinder base
Pre-units....generic term for all non unit construction twins, 500 and 650s
Swing arm preunits.
Duplex preunits 1960-62
Unit construction, sidebag oil tank.
OIF. Oil in Frame.
Long rod engines, pre unit and unit
Short rod engines
Electric Start engines
Late 650 Thunderbird, short rod engines. (reduced bore)
Singles
Triples

Lots of other subgroups, Daytonas, Bonnevilles, TTs, but these are individual models.

 

[Sheepdog]

Mecchanica is right on, though not quite connected to a chronology. Speed Twin: 1938 (500cc), Thunderbird: 1950 (650cc), Tiger T110: 1954 (650cc), 1959 Bonneville T120 (650cc, dual carb), 1963 Unit Construction Bonneville T120 (650cc), 1968 Daytona T100R (500cc dual carb), 1973 Bonneville T140V (750cc 5 speed), 1982 Bonneville T140 TSS (750cc 8 valve). 1983 marked the end of the Meriden manufacturing period.

When John Bloor took over Triumph production in Hinckley, Leicestershire, England he limited models to three and four cylinder models of a less traditional design. However, In 2001 the New Model Bonneville was introduced. This brings us to the present.

Hope this puts things in better perspective...