What Year Is My Classic Motorcycle?

Dating your classic bike is an important part of any restoration or even buying parts. Finding the right parts for your bike is so much easier if you know what bike you have, especially if you then use a genuine factory parts book to then use OEM part numbers to place your order.

Buying the incorrect parts is an expensive and time-consuming process and should be avoided where possible. Below you will find how you can identify what bike you have and the year of it using your engine / frame numbers.

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Triumph Engine Dating

What Year Is My Triumph?

If you are looking to buy Triumph Motorcycle Parts you should know what bike you have. This guide will help you to identify the model and year of your Triumph using your engine and frame number.

Where is the Triumph Engine Number Located?

Triumph engine / VIN numbers can be found on the left hand side of the crankcase, just below the barrel. It is usually 6-7 characters long and if it is as original, the frame number will be the same as the engine.

The frame number is usually located on the left side of the headstock.

How to read a Triumph engine number

Multiple systems were used for Triumph engine numbers throughout the years. In most cases, the engine number has the model prefix, whilst the frame may just have the letter T, or nothing at all. Special models may also carry an additional letter, such as P for Police, or C for High Compression.

Triumph Dating

Prewar Singles and Page twin

Year   Model   Engine number    Frame
1934   6/1        1V4
1935   6/1        1V5
1936   6/1        1V6
T70       T1L6                      L
T80       T2T6                     S1
T90       T5S6                     S11
1937-40   For all models the engine had the model code as a prefix plus a year number such as 7, 8, 9 and 40 to cover the years concerned, then then the serial number

Triumph Twins for 1938-49

For these models the engine had the model code as a prefix plus an indication of the year in the form of the last one or two digits of the year. Generally the prewar models will have an 8 or 9, and the postwar a 46,47,48 or 49.

The prefixes used were T or 5T for the Speed Twin, T100 for the Tiger 100, 3T for the 350 twin and TR5 for the Trophy.

Postwar engine numbers as follows:

Year        Engine Number
1946        72000
1947        79046
1948        88782
1949        100762

Triumph Twins for 1950-69

1950 saw a new numbering system with just the model code as the prefix and the serial number.

Year Unit 350 & 500cc Pre Unit 500 & 650cc
1950 —— from 100 N
1951 —— 101NA – 15808NA
1952 —— 15809NA – 2500NA then 25000 – 32302
1953 —— 32303 – 44134
1954 —— 44135 – 56699
1955 —— 56700 – 82799
1956 —— 70930 – 011115 then 0100 – 0944
1957 H101 – H760 0945 – 011116
1958 H761 – H5484 011116 – 020075
1959 H5484 – H11511 020076-029363
1960 H11512 – H18611 029364 – 030424 then D101 – D7726
1961 H18612 – H25251 D7727 – D15788
1962 H25252 – H29732 D15789 on Unit 650cc
1963 H29733 – H32464 DU101 – DU5824
1964 H32465 – H35986 DU5825 – DU13374
1965 H35987 – H40527 DU13375 – DU24874
1966 H40528 – H49832 DU24875 – DU44393
1967 H49833 – H57082 DU44394 – DU66245
1968 H57083 – H65572 DU66246 – DU85903
1969 H65573 – H67331 DU85904 – DU90282














Singles, Twins & Tridents for 1969-83

For 1969, another new system was introduced using a two letter prefix for the month and model year, followed by model type and serial number.

The first letter is for the month and the second for model year which ran from August of the previous calendar year to the following July. July 1980 onwards saw and additional letter added to the exisitng two and was used for the larger unit singles, twins and triples.

Letter Month Model year
A January Aug. 1978 – July 1979
B February Aug. 1979 – July 1980
C March Aug. 1968 – July 1969
D April Aug. 1969 – July 1970
E May Aug. 1970 – July 1971
G June Aug. 1971 – July 1972
H July Aug. 1972 – July 1973
J August Aug. 1973 – July 1974
K September Aug. 1974 – July 1975
N October Aug. 1975 – July 1976
P November Aug. 1976 – July 1977
X December Aug. 1977 – July 1978
KDA 1981 models Sept. 1980 – Apr 1981
EDA 1982 models May. 1981 – Jan 1982
BEA 1983 models Feb. 1982 – Jan 1983
T140V AEA34393 DU24875 – DU44393Last model Jan 21 1983



Triumph Singles

Year Engine Number Model
1953 101 T15
1954 101 T15,T20
1955 8518 T15,T20
1956 17389 T15,T20
1957 26276 T20, T20C
1958 35847 T20, T20C
1959 45312 T20, T20C
1960 56360 T20, T20S
1961 69517 T20, T20T, T20S/L
1962 81890 T20, T20S/S, T20S/H, TR20, TS20
1963 88347 T20, T20S/S, T20S/H, TR20, TS20
1964 94600 T20, T20S/S, T20S/H, TR20, TS20
1965 99720 T20, T20S/S, T20S/H
1966 101 T20, T20S/S, T20S/H, TR20, T20S/S
1967 T20S/C
1968 T20S/C


Triumph TRW Dating

See the Classic Bike History page for more Triumph TRW information

Year Engine Number
1950 14401N-14459N
1951 6044NA-14320NA
1952 22001NA-22838NA
1953 22839NA-23273NA
1954 23274NA-23322NA



Triumph Tigress Scooter Dating

  TS1   TW2  
Year Engine Number Frame Number Engine Number Frame Number
1959     W101 101T
1960 S101 4001 W3201 4001T
1961 S6720 18801B W11790 18800T
1962 S11407 30140B W17800 30140T
1963 S12498 31825B W18435 31825T
1964 S13263 33661B W19793 34286T
1965 S13576 34300B   (last)
Last   34468    

TW2S engines with electric start have letter E suffix


BSA Engine Dating

What Year Is My BSA?

Identifying your BSA is an important part of owning a classic bike. If you are on the hunt for BSA Parts it is essential to know what bike you have to make sure that you are ordering the right parts. 

Find the guide below for dating your BSA.

BSA A50/A65 Dating

Model 1962 1963 1964 1965
A50 A50-101 A50-823 A50A-101 A50A-686
A65 A65-101 A65-1947 A65A-101 A65A-1134
A65R     A65B-101 A65B-334
    A65C-101 A65C-1082
A65T/R     A65B-101  
A50C     A50B-101 A50D-101
A65L/C     A65D-101 A65D1742
A65S/H     A65E-101 A65E-701
A50CC       A50B-507
A50C/CC (UK)       A50DC-101
A65L & A65LC       A65DC-2158










Model 1966 1967 1968 1969
A50 Royal Star A50R-101 A50RA-101 A50RB-101 A50RC-101
A50 Wasp A50W-101 A50WA-101 A50WB-101  
A65 Thunderbolt A65T-101 A65TA-101 A65TB-101 A65TC-101
A65 Lightning A65L-101 A65LA-101 A65LB-101 A65LC-101
A65 Hornet A65H-101 A65HA-101    
A65 Firebird     A65FB-101 A65FC-101
A65 Spitfire A65S-101 A65SA-101 A65SB-101 A65D1742








Post-1969 models changed the numbering system again with a two letter prefix to denote the month and year of manufacture.

For example, a BD prefix would be a February 1970 manufactured bike

Letter Month
A January
B February
C March
D April
E May
G June
H July
J August
K September
N October
P November
X December


Letter Model year
C Aug. 1968 – July 1969
D Aug. 1969 – July 1970
E Aug. 1970 – July 1971
G Aug. 1971 – July 1972
H Aug. 1972 – July 1973

It is also worth noting that from 1971 the Oil in Frame models replaced the oil tank models.

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