Machine Numbering Sequence
Due to discrepancies in the original factory records, it may never be possible to have a fully accurate database of engine and frame numbers, although what this section of the website will do, is provide a guide to those wishing to date their machines from the frame and engine numbers stamped into them.
What is known is that the Triumph factory at Meriden used one continuous series of numbers for all T15 Terrier and T20 Tiger Cub machines starting in July 1953 with Terrier T15 101 and going all the way through the Tiger Cub line to 100013.
The frame numbers were all preceded by the letter 'T', whereas the engine numbers were preceded by the model designation, e.g. T15, T20, T20C, etc.
At some time in 1964, Triumph's parent company BSA, decided frame numbers would also include and be preceded by the model designation; replacing the sole letter 'T' with 'T20'.
Machines produced after number 100013 took the BSA format of numbering. One that didn't use a continuous sequence but instead a rather confusing system that started at 101 to 2000, then 2001 and 3001.
Unfortunately the BSA records make it impossible to give a totally accurate assessment of when each machine was produced due to the opening and closing serial number date not being recorded.
What is known is that the Triumph factory at Meriden used one continuous series of numbers for all T15 Terrier and T20 Tiger Cub machines starting in July 1953 with Terrier T15 101 and going all the way through the Tiger Cub line to 100013.
The frame numbers were all preceded by the letter 'T', whereas the engine numbers were preceded by the model designation, e.g. T15, T20, T20C, etc.
At some time in 1964, Triumph's parent company BSA, decided frame numbers would also include and be preceded by the model designation; replacing the sole letter 'T' with 'T20'.
Machines produced after number 100013 took the BSA format of numbering. One that didn't use a continuous sequence but instead a rather confusing system that started at 101 to 2000, then 2001 and 3001.
Unfortunately the BSA records make it impossible to give a totally accurate assessment of when each machine was produced due to the opening and closing serial number date not being recorded.
Production years started on 1st August of the preceding year until 31st July of the actual year, e.g. the 1954 production year actually runs from 1st August 1953 through to 31st July 1954, 1955 production year runs from 1st August 1954 through to 31st July 1955, and so on.