Dating Your Triumph

Gil Stratton checking over the Rheingold Beer Triumph with Miss Rheingold 1956 Hildegarde Mahoney.
The information below will allow buyers and owners to confirm the year of production of most post war Triumphs built at Meriden and is taken from reliable sources.
This assumes that you have a genuine numbers, after 1950 all Triumphs leaving the factory have matching Engine and Frame numbers and any miss match will indicate a machine made from two or more motorcycles, buyers are advised to check numbers carefully.

Triumph make models for a number of markets, and home and overseas machines are made on the same track. A difference of only one numeral could separate your model from one built to, say, American specification. Motor Cycle 1965

A Range… Terriers and Cubs 150 and 200cc… Prefix T… T20, T20SS, T20J
1954 101 to 8517
1955 8518 to 17388
1956 17389 to 26275
1957 26276 to 35846
1958 35847 to 45311
1959 45312 to 56359
1960 56360 to 69516
1961 69517 to 81889
1962 81890 to 88346
1963 88347 to 94599
1964 94600 to 99719
1965 99720 to 2718
From 1965 Cub Production Transfers to BSA at Small Heath

B Range… Twins 350cc, 500cc and 650cc Twins… Various Prefixes.. 3T, 5T, 6T, T100, T110, T120

No Series Code… Pre Unit Twins 1952 to 1956, Rigid, Sprung Hub and Swing Arm Frames
1952 25001 to 32302
1953 32303 to 44134
1954 44135 to 56699
1955 56700 to 70929
1956 70930 to 82800

O Series… Pre Unit Twins 500cc and 650cc 1956 to 1960, Swing Arm Frames
1956 101 to 944
1957 945 to 11115
1958 11116 to 20075
1959 20076 to 29363
1960 29364 to 30424

D Series… Pre Unit Twins 1960 to 1962, Duplex Swing Arm Frames
1960 101 to 7726
1961 7727 to 15788
1962 15789 to 20314

DU Series… Unit Construction Twins 1963 to 1969
1963 101 to 5824
1964 5825 to 13374
1965 13375 to 24874
1966 24876 to 44393
1967 44394 to 66245
1968 66246 to 85903
1969 85904 to 90282

C Range… 350 and 500cc Unit Construction Twins… Prefix H… T21, 5TA, T100A, T100SS, T100C.
1957 1 to 760
1958 761 to 5480
1959 5481 to 11511
1960 11512 to 18611
1961 18612 to 25251
1962 25252 to 29732
1963 29733 to 32464
1964 32465 to 35986
1965 35987 to 40527
1966 40528 to 48728
1967 48729 to 57082
1968 57083 to 65572
1969 65573 to 67331

1969 to 1980 Twins
During 1969 the engine numbering system changes to a mixture of letters and numbers indicating month and year of manufacture.
There were Factory errors at times and the chart below is only a guide to the letter codes.

A January C 1969
B February D 1970
C March E 1971
D April G 1972
E May H 1973
G June J 1974
H July K 1975
J August N 1976
K September P 1977
N October X 1978
P November A 1979
X December B 1980

From 1969 the numbering is still sequential but shared between the various models and sizes of Twins so that the different ranges are now combined under a
common system. As usual, production for the next year begins in September/October
Note that the late Triumph unit Singles and Triples are manufactured by BSA and appear in the BSA Factory Records.

The Font used by Triumph on their stamps though it changes over time is very distinctive and with practice you can soon identify numbers that are problematic. I have added a gallery of engine number photographs taken by myself over many years that illustrate the correct number style. None of the images have been edited except to reduce the file size for publication and they have been selected for clarity from my extensive personal collection. It is surprisingly difficult to take clear and consistent photographs of Engine and Frame numbers and you should always ask permission of the owner of the machine if you can.

Most machines leave the factory soon after assembly, a few machines were stored at the factory and the dispatch date can be several months after machine assembly.
Press and Display machines are frequently not recorded in the dispatch book or are sent to select dealers up to two years later…
A few machines such as the pre-production Tiger 90 and 100A were converted from other models and others machines were supplied for conversion to race machines and special duties; you may unwittingly and happily have a particularly historic machine.

The Engine/Frame numbers above, denoting the start and end of annual production are based on the numbers quoted in many sources, these are derived from the factory records and parts books, information supplied by John Nelson confirms these numbers. But the end of one year’s production and the beginning of the next is not set in stone and machines made close to the change-over period need to be checked carefully. I have come to the conclusion that the Engine/Frame number should be used with care and as a guide to year specification.

The Engine number followed by the Frame number should be your main point of reference for dating the machine. The Engine number was stamped first and the Frame stamped with the same number as the machine neared completion. Complete standard machines at no time left the factory with differing numbers! The Engine number is stamped in two operations; the model code (T90 etc); is usually (Not Always True) made by a single stamping and the figures should be neatly aligned and even. The H numbers are individually stamped and therefore variable to a degree. Look closely at the style of the lettering it is very distinctive! With some expertise it is possible to date the engine from the style of the stamping used.

The B and C range twins being built in sequential batches on the same assembly line will have Engine and Frame Numbers that use the same stamps, at least until the stamps are changed, which happens periodically. With experience you can also identify when a different “hand” has taken over the work as the layout changes.

Engine numbers finishing with a W indicate that this is from a radio-equipped i.e. Police machine. While the distinctive “Wheel” mark on early B Range machines indicates that Ramp Type Camshafts are fitted. Pre-War and early Post-War Twins show a Year Code before the Engine Number, these can be confusing until you understand the system.

After 1968 when Triumph changed the system to include date codes the lettering style changes slightly and the stampings are over a background making erasing the stampings more difficult. The B range Twins have the stampings on a raised plate that is a distinctive crankcase feature from this period.

I am collating a series of engine and frame number photographs covering the period from 1950 to 1970 so that in the future it will be possible to confirm
the originality of a ‘Stamping’ against other examples from the same day/batch, this is already identifying ‘Worrying’ numbers….
In order to save your-self a lot of grief, before committing to purchase a machine I recommend contacting the VMCC or the TOMCC with details of the Engine and Frame number. There are some particularly good fakes out there especially for the more collectable models.

Look for the casting date marks, these small circular marks (the size of button) usually show a two figure Year code i.e. 63 which is surrounded by a series of raised lines to indicate the month. You will find casting date marks on the crankcase halves, visible just behind the clutch and exhaust timing pinion, on the larger triumphs there is a date mark within the inlet rocker housing (But not on the ‘C’ range machines) Crankcases are additionally marked as a pair with numbers on the lower engine mounting if these are not matched then it is likely that one half has been changed during the life of the machine. I am investigating further marks on crankcases, cylinder heads and crankshafts.

The crankcase (Casting) pattern was made up of a number of interlocking parts, allowing one part of the crankcase to be changed without affecting the remainder. I have been able to identify some of the detail differences applied over the years to the ‘C’ range Crankcase, these include the area of the rev counter drive, tdc point, relief valve and later breather arrangement.

The engine and frame numbers can only be a guide to year specification, As the machines were made in batches separated by other models there are often subtle variations in specification from one batch of the same model to another where later specification parts have been used as they have become available. It is important to understand that different finishes and parts apply to export models and changes were also made during the year, as part of a warranty claim (1963 Tanks) or by the dealer to shift old stock or at the request of the owner before acceptance. Many anecdotes indicate that if parts were not available on the production line alternative items were then fitted. My discussion with John Nelson has indicated that this DID NOT happen as sufficient parts were prepared to complete each batch of machines.
If your machine appears to be unusual than it is because it has been changed during its lifetime or is from a particularly batch.

The VMCC are able to provide a comprehensive Research, Dating and Registration Service for most makes of motorcycle from 1900 onwards.
Certified Copies of the Factory Records for Ariel, BSA, Triumph and Norton are available either for personal use, display or for use in obtaining a Registration Number
In addition the VMCC are in contact with numerous model experts and one make clubs throughout the world.

The production of the original parts books uses a particularly interesting process. Large ‘Master’ Technical Drawings (A3 Size) are made representing each page of the parts book so that all components are accurately portrayed. Small parts are drawn ‘Life Size’. The Drawings are then photographed and reduced to the size corresponding to the parts book pages.
Each year, rather than re-drawing the pages completely, new parts are drawn separately and ‘Stuck’ onto the ‘Master’ or sections of each component are carefully pasted over and re-drawn. Photographs are then taken and reduced as before.
You will see that pages of the parts books from one year to the next are almost identical except for where components have been added or parts re-drawn.
Some parts illustrated do not change to represent what the later parts actually looks like and care needs to be taken.
It is more useful to note the change in Part Number as this will mean a new design of part has been used, even if the Image is unchanged. For an example look at the fork shroud part number between Parts Book 5 and 7.
Additionally Dealers especially in the USA would be provided with a Bulletin detailing those parts applicable to or omitted from US Models. Refer to the Bulletin Page for details and an index.

All period Lucas equipment will show a date mark in addition to the part number ie 265 for Feb 1965 Look for these on Horns, Coils, Alternators, switches etc. I have collected the period Lucas Catalogues from 1963 to 1968 and can advise on the equipment fitted each year and provide scanned copies if you require them.
The VMCC in their library have very useful bound copies of the Lucas Brochures for most UK Manufactures, contact the VMCC for help.

The DVLA (UK only) are no longer able to provide you with information they hold on a vehicle you own, this included previous owners.
The old logbook copies (if they exist) will also show the original colour scheme and any changes made during the life of the machine affecting taxation class.
The DVLA Website can also be helpful to identify if a registration is current and this can be correlated with the registrations for the county/area to verify a machines identity. Local Records sometimes still exist which can also lead to interesting facts.
(UK Bikes) Occasionally machines lose their original registrations, it is possible to recover these as long as the registration is available and you have sufficient documentary evidence to present a case. Sometimes Registrations can also be traced from the factory records. Richard Wheadon, the Registrar of the Triumph Owners Club is an expert in this field and can conduct research on your behalf, contact him at he will require a photograph or rubbing your engine and frame numbers.
He can also assist in the dating and verification of any model of post war Triumph.

Many UK owners assume that the registration number dates the bike …. WRONG !
It is important to understand that many machines were not registered until they were sold; which could take anything up to 2 years or even later.
Other machines made early in the production year (September) and sold quickly will appear to have incorrect registrations until you understand that before 1967 registrations ran January to December (It is more complicated than this, see below)

The registration system used in the UK (60’s) typically uses the last two letters to identify the County or City the vehicle is registered in, with each County or City allocated several pairs of letters.
i.e Cornwall uses AF, CV, and RL, at the beginning of each series you would have AAF, ACV, ARL with numbers 1 to 999 being allocated firstly to AAF then ACV and lastly ARL, then you start again with BAF, BCV and BRL then CAF, CCV and CRL etc.
Each cycle for a three pair County or Town will give 3000 registrations (All Vehicles). The Warwickshire records for 1964 show some 2000 registrations a month !
Things get a bit more complicated with the introduction of the ‘A’ Suffix in 1963 as not all counties or areas use these if there are sufficient ‘Old’ Numbers to use up.
If the suffix does start to be used the system starts with A for example AAF1A then AAF2A until you reach AAF999A, hopefully you are still with me at this point.
Now stuff really does get complicated …. It is possible to place registrations in date order not just by the suffix but also by the first letter as we know that they are part of a series, you can be confident that FRL123D follows CRL123D.
Unfortunately as each Registration office worked in splendid isolation some would use up their Series faster than others so that the first letter for one County does not match the next County or any other and the dates when a new series begins can only be determined by looking at the original records if they survive.
Additionally larger garages, manufacturers or dealers would be allocated a batch of registrations to use as required only completing the record once the registration had been fitted to a vehicle, in the records I have seen there can be several weeks between one registration date and the next even though the numbers are sequential!

The Registration Records (If they survive) are held by the various County Record Offices, from my research I have noticed that the records do not follow a standardised form and some records do not record the Engine/Chassis Number making correlating information with the factory records more difficult.
Researching registrations can be fascinating and you may find a trip to your local record office rewarding.

The VMCC in their Archive have a very useful file (Glasses Guide) containing the date periods for all UK registrations, this can help to narrow down a registration to within a few weeks, the Library will also be able to advise if original registration records still survive for any given area.

Optional parts abound on Triumphs both factory supplied parts or from many other proprietary suppliers. The Triumph factory records now held by the VMCC and Triumph OC are helpful in identifying an individual machines manufacture date, dealer destination and optional extras factory fitted. I have detailed the advertised optional extras but these may differ from what was available or fitted as standard. I have a parts supplement detailing numerous other optional items for the T90 and T100SS, and also copy of Technical Bulletin No:13 (Prep and Assembly for maximum performance) which goes into some detail the Factory options available.
The Factory also offered a fork-exchange and engine exchange service, which may mean that later components were factory fitted or reconditioned.

In conclusion, my interviews with original owners have shown that machines were often customised and modified as fashion and individual finance dictated. Accidents, age and mechanical failure also take their toll on the original components and most machines surviving today are far from original and standard. Enjoy your machine for what it is and hopefully it can continue to give pleasure to you and others for many years to come.