Triumph engine number dating
Sometimes they were despatched months earlier or later so the lettering system should just be taken as a rough guide. There was a short period where the engine marking matched the frame marking but the frame prefix was A50; Presumably to use up stock in store prior to the changeover.
B25FS through to 1971Victor Special B44VS 1969 (C) November 1968 through June 1969 then 1970 (D) July 1969 to July 1970Shooting Star B44SS 1969 (C) November 1968 through August 1969 then 1970 (D) July 1969 through July 1970Gold Star 500 B50SS 1971 to 1972Victor 500 B50T 1971 to 1972Victor MX B50MX 1971 to 1973Early post war machines up to Z series had the frame stamped similar to the plunger or sprung frames e.g. Machines still in stock in the 1967 season (about 1000) were resold in the 19 season.
all A series models have A7 or A50 prefixes with the exception of the Rocket Gold Star and Super Flash.
Owners with late model BSA's can easily identify the month and year of their machine as the factory adopted a dating system for frame and engine numbers for the 1969 season models.
We will supply back to you on Museum letterhead a statement of whether the number is from the lists in our files.
I am going to sell the barrels and pistons, as I don't believe the bike to be a T120rt, as it is a tiger and not a bonneville.
“If you have a machine you feel may be from the 200-and-some machines in the batches of RTs prepped on the east and west coasts we will compare those numbers to the lists for you.
Please send us your serial numbers and state whether they are with a chassis, and if yes, what chassis number in cases where the engine is in a frame other than original.
Recently the list, probably complete, was discovered in the AMA Homologation files that were transferred to the Motorcycle Hall of Fame Museum about 20 years ago.
One collector has already told me this list is the ‘Holy Grail’ of Triumph motorcycle collecting and will be useful in identifying which machines were officially modified, with a suffix added to their serial numbers.