Can someone please advise me the difference between say a 1979 T140D and a T140E.
Hello Burt,
The 1979/80 T140D (Bonneville Special) normally had the small US style fuel tank, US handlebars, a two into one exhaust system, Lester cast alloy wheels, black paint job with gold pin striping, plus a few other minor styling differences to the 'E' models, although some D's built for the UK market had the larger UK/general export fuel tanks and standard two into two exhaust system.
Also how does one read the engine/ frame numbers to ascertain the specifications of the bike, i.e. build date etc
You can tell the build date (to the nearest month) from the two-letter engine/frame number date code prefix.
However, various sources often list the build date prefixes, but unfortunately tend to leave out the necessary information on how to interpret them, which can often mislead an owner into believing that his/her T140/TR7 was built a year later than it actually was!
To explain, Triumph (and BSA) production of their new 'year' models usually began when the factory re-opened after the summer holiday shutdown period during the preceding year, so bikes built from
approximately August(J) to December(X) would be stamped with the
new year prefix letter, but were actually
built during the 'old' calendar year!
Note that 1979 D & E model year production started in July of the preceding year instead of August (J), at 'HA' 11001 (H = July, A = 1979 model year) so HA actually indicates a build date of July
1978.
Triumph serial numbers and date codes:
http://www.tioc.org/serial_numbers.htmThe actual model type i.e: T140V, T140D, T140E etc. should also be stamped on both the engine and frame, and both serial numbers would have matched when the bike left the factory.
