Coulers - Frame + Engine Numbers


2/1, 3/1, 3/2, 5/1, 5/2: Petrol tank black with three grey panels lined in gold. Rest black. 

5/3, 5/4, 6/1: Petrol tank black and chrome with 3 single lined gold panels. Wheels chromed with black centre gold lined.

2/5, 3/5, 5/5: Petrol tank plum and chrome with 3 single lined gold panels. Wheels chromed with plum centre gold lined.



L2/1, 2/1, 3/1, 3/2, 5/1, 5/2: Petrol tank black with 3 single lined gold panels. Wheel rims black.

2/5, 3/5, 5/5: Petrol tank plum and chrome with 3 single lined gold. panels. Wheels chromed with plum centre gold lined.

5/3, 5/4, 6/1: Petrol tank black and chrome with 3 single lined gold. panels. Wheels chromed with black centre gold lined.


L2/1, 2/1, 3/1, 3/2, 5/1, 5/2: Petrol tank black with 3 single lined gold panels. Wheel rims black.

5/5, 6/1: Petrol tank black and chrome with 3 single lined gold panels. Wheels chromed with black centre gold lined.



Tiger models: Petrol tank panelled in silver sheen, lined out in blue. Mudguards black with silver sheen centre stripe lined out in blue. Wheel rim centres in silver sheen, lined out in blue. 
De Luxe models: Petrol tank panelled in plum, lined out in gold. Frame, mudguards and wheels finished in black.
NB. chrome rims with enamelled centres offered as optional extra on de Luxe models. 



Tiger models: As 1937.
5T Speed Twin: Entirely finished in amaranth red. Petrol tank panelled in Amaranth red, lined out in gold. Wheel rim centres in Amaranth red, lined out in gold. 
De Luxe models: Petrol tank panelled in plum, lined out in gold. Frame, forks and mudguards finished in black. Mudguard centres in plum, lined out in gold. Wheel rim centres in plum, lined out in gold.



Tiger models: Petrol tank panelled in silver sheen, lined out in blue. Mudguards in silver sheen with black centre stripe. Wheel rim centres in silver sheen, lined out in blue.
5T Speed Twin: As 1938.
De Luxe models: Petrol tank panelled in black, lined out in ivory. Frame, forks and mudguards finished in black. Triple ivory line to mudguard centres. Wheel rim centres in black, lined out in ivory. 

5T Speed Twin and Tiger 100: as 1938.
3T deluxe: as 1939 deluxe models.
T85: as Tiger 100



6T Thunderbird: All in thunder blue.
5T Speed Twin: All in amaranth red.
T100: Petrol tank in silver sheen, mudguards silver with black rib. Wheel rims with silver centre lined blue. 



As 1950 except: 6T Thunderbird now in polychromatic blue and Shell Blue Sheen


TR5 1950 –1953 
Petrol tank silver sheen panels lined in blue


1937 –1940 Petrol tanks
The three painted panels are lined out with a double parallel stripe. The thicker stripe is bisected by the edge of the painted panel, in other words, it covers the edge of the painted panel and is 3/16'' (5mm) wide. The second, thin stripe is outside it, on the chrome and is 3/64'' (1.5mm) wide. The space between the two is 1/8'' (3.5mm). The shape of the side panels is particularly subtle and echoes the shapes around it. The most common error is to paint the panels too small whereas the factory job left quite small areas of chrome showing. The lining was done very quickly and although beautifully executed it would not be necessarily symmetrical.

The lining on the mudguard rib varies : On the 'deluxe' models (5H, 6S etc.) the rib has a centre stripe 3/10'' (8mm) wide with parallel stripes 3/32'' (2.5mm) wide either side, with a gap of 3/16'' (5mm) between the centre stripe and the outer stripes, whereas the Speed Twin has only the outer stripes. Where the machine colour was black, the lining was ivory white (not bright white). With the machine colour in Amaranth red the lining was always gold.


The Tiger models with silver/black mudguards are more difficult to specify. I have seen evidence of two different blues used for the lining. Some seem to have had a dark blue stripe on the tank with no blue lining to the mudguard rib, others a brighter, mid-blue stripe which also appeared on the mudguard, edging the black centre rib. 


The rules for paint colour finishes are not hard and fast. For example the range of Tiger singles for '37 and '38 are usually seen with silver mudguards but it appears from the catalogue that they had black mudguards with a silver rib. In fact, contemporary reports and other evidence suggest that both versions appeared in both years. It is only the choice of catalogue illustration that implies the rigid division between the two colour versions. More interestingly, I have found evidence of components painted amaranth red over a black base and vice versa indicating that small batches were re-finished on an ad hoc basis to fulfil orders. 


One of the most common errors in paint finishing is the tendency to paint all components on the Speed Twin in the Amaranth red, whereas quite a few parts were finished in black, including: Both number plates, fork spring, pillion footrests, horn, voltage control box, speedo, seat frame, rear stand spring and the Lucas DC40. 


The paint finish itself is quite particular. The silver colour for the Tigers was applied as one solid colour rather than the translucent lacquer over a base-coat so popular now. This gives a slightly dull metallic grey/silver look that is much more authentic. Similarly, the plain colours had a very distinctive look achieved by applying thinly to preserve the detail, with a deep shine rather than a high mirror gloss.


The paint also seems to have been very tough and would resist a good bang with a heavy tool unlike most modern finishes. The lining/pinstriping had a semi-matt/eggshell quality rather than being glossy. It is very difficult to communicate the colours themselves: The Amaranth red applied to the Speed twins has an identical comparison in an Isuzu colour called 'Red Mahogany'. The Tiger silver is more difficult as the colour deteriorates with age and comparisons with original components aren't much help. I have ended up using a VW colour 'Satin Silver'.


Frame & engine numbers 1934-1936
There were four frame designs during this era: All 500cc/550cc and 350cc OHV used the same frame.  250cc and 350cc SV used a lighter frame. Both the L2/1 and the 6/1 were each fitted with unique frames. 

The 500ohv/550sv/350ohv frame (part F848) carried an S (standard) prefix engine number for machines with the 500cc/550cc engine, but an SL (standard light) prefix for machines with the 350cc ohv engine. The same frame but with a different number prefix according to which engine was fitted. Very confusing.

The 250/350sv frame (part F1068) always carried an SL (standard light) prefix. 

L2/1 frames (part F1373) are prefixed L and 6/1 frames have a V prefix. 

Engine numbers too included engine size codes:
R for 250cc.
L for lightweight 250cc.
T for 350cc.
S for 500cc/550cc.
V for 650cc.

The engine number starts with the mark number: at that time Triumph grouped 2/5, 3/5, 5/5 etc as the Mark 5 range, and the 2/1, 5/1 etc as the mark 1 range, and so on. Then the engine size code (above), with a year code, which is the last number only of the year (eg 5 for 1935). So, for example, a number beginning 4. S5 is a 1935 model 5/4. Similarly, a number beginning 1. R4 is a 1934 2/1. This complicated sequence is then followed by the engine number itself, limited to four digits or less. Frame numbers advanced at a greater rate (not quite twice as fast but something close) than engine numbers (the opposite to post 1937-40 practice) which implies that engine numbers used more than one sequence. If so it seems there was only one frame number sequence for all, apart from the 6/1 which was entirely seperate. I have frame numbers running up to around 5600 on my register which implies a total production run of about 6000 including all models.

The introduction of the Tiger models then resulted in an additional T prefix in front of the whole sequence. Tiger 80s used a 3/2 single port engine basis (so T2. T6. 2999 would be a 1936 Tiger 80) and Tiger 90s used a 5/5 twin port basis (so T5. S6.2999 would be a 1936 Tiger 90)

Frame and engine numbers 1945-1953

The TF frame appeared post war on the 5T & T100 with some small changes. (see frames). The new 3T used the lightweight frame from the T70/T80 era and continued with the TL prefix until 1948

Most sources state the post-war machines started at TF 4500 in 1945 but I have come across post-war bikes with lower numbers. From my research pre war TF frames reached just over 4300 in 1942 and post war machines picked up from there.

There is some variation on estimates of engine/frame number runs by year for the early post-war years. However Peter Gallagher in Australia has done some good research consulting contemporary sources, including individuals and written records, and has come up with the following sequences as the most likely and I am indebted to him for allowing me to reproduce the information here.

1946 engine numbers started at 46-5T 72001
1947 engine numbers started at 47-T100 79046
1948 frames from TF 15001 to TF 25000
1948 engines from 48-T100 88782 to 102235
1949 frames from TF 25001 to TF 33615
1949 engines from 100762 to 113386

For 1950 Triumph introduced matching frame and engine numbers. Frame/engine numbers started with 1001N and went to 16100N. Engine numbers included a model type prefix. So 6T-1212N is a 1950 Thunderbird (used to be mine, where is it now?) The ‘N’ suffix then acts as the year code

1951 then started again but with a ‘NA’ suffix and ran from 101NA to 15807NA.

1952 continued the NA suffix and ran from 15809NA to 25000NA so 1952 is the first year that Triumph didn’t use a date code (apart from 1949, when the lack of date code differentiated them anyway, plus running into six figures). Then, during the '52 model run the NA suffix was dropped at 25001, running to 32301. Apparently overseas dealers were sometimes finding they had stock showing the previous years numbers which didn’t look good.

1953. 32303 - 44821

1954 44822 - 55493

The model 3T used the TL prefix until 1948 then changed to a TC prefix. The TR5 also used a TC prefix but a T suffix

Frame and engine numbers 1937–1940
From October 1936 the whole range was divided into two types of frame: heavyweight and lightweight, although this time both frames used separate numbering sequences running in parallel.

Heavyweight models (ohv 500cc/sv600cc) frame coded TH (Triumph Heavy)
Lightweight models (ohv250cc/350cc/sv 500cc) frame coded TL (Triumph Light)
The numbering probably started with TH 101 and TL 101.
Engine numbers too started with 101. Each engine number is unique, that is to say one numbering sequence ran through all models. In other words, engine number 10778 might be a 5T, 10779 might be a 3H. In this way engine numbers progressed at roughly twice the rate of frame numbers as both types of frame had a separate sequence. The engine number is always preceded by the year and model code so an 8-5T prefix denotes a 1938 5T. Triumph used year codes in their engine numbers for sixteen years (with the exception of 1941 and 1949) up to 1951, and it’s important to understand that this code denotes the model year, not the calendar year. For Triumph (and most of the British motorcycle industry) the model year started with the Olympia show at Earls Court in October or November of the previous year and so the 12 month period during which you could buy a 1939 Triumph was actually October 1938 - September 1939.
1937 TH frames went to approximately TH 2390. 1937 TL frames went to TL 3640. 1938 TH frames went to about TH 6735. 1938 TL frames went to TL 7690

In October 1938 a new, third type of frame was introduced for the 1939 T100 with a TF (Triumph frame) prefix to differentiate it. A new, third, numbering sequence for this frame starting from the beginning again, TF 101. However, the new Tiger 100 engine continued the existing engine numbering sequence, so early Tiger 100s showed long engine numbers (around 15600) but short frame numbers.

1939 TH frames went to about TH 10175. 1939 TL frames went to TL 11642.   1939 TF frames went to TF 2255.

For 1940 on, all heavyweights in the range (now reduced to 5T, T100 and 6S) used the TF frame. The lightweight range continued more or less as before. 
1940 on TF frames went to TF 4313 in 1942. TL (civilian) frames went to TL 17090.
NB. A few 5T Speed Twins at the end of the 1939 season (with '39 engine numbers) went into TF frames. These are numbered in the 22000/23000 range

Production and sales for civilian models continued into 1941 and perhaps even 1942. However, for obvious reasons the process was disjointed. I have come across one or two '41 numbered engines but it seems Triumph dropped the date prefix on engine numbers around about engine number 31100. Some late 1940 models and nearly all 1941 models therefore don't show a date code. Probably because of the extended delays between production and sales. Engine date codes were resumed in 1945 with a '45'  prefix.

Pre war Turner Triumph engine numbers went to just over 31,000 by the early 1940s. As this reflects total sales for a roughly four year period it’s interesting to compare it with the previous three year period when less than 20% of that number of sales was achieved. A tribute to the success that Edward Turner achieved with the company.

NB A 'C' suffix to the engine number denotes combination (sidecar), indicating a lower geared drive sprocket fitted. 

Frame numbers are stamped horizontally at the top of the headstock and again across the back top of the saddle tube.

Triumph Dating
Engine Frame numbers
1937 to 1949
The year and model were used as a prefix to the engine number
From 1937 to 1939 the final digit ( 7, 8 or 9 ) was used.

From 1946 to 1949 the final two figures ( 46, 47, 48 or 49.)

The model numbers were T or 5T for the Speed Twin, T100 for Tiger 100, 3T for 350 twin & TR5 for Trophy.

Typical numbers were thus:
8-T-1234 ( 1938 Speed Twin )
47-5T-23456 ( 1947 Speed Twin )
9-T100-45678 ( 1939 Tiger 100 )

Pre-war frames ( 1937 / 39 ) used the prefix TH for the 500cc models ( 5T & T90 ) and TF for the Tiger 100.

Engine numbers commenced at:
1946 - 72000
1947 - 79046
1948 - 88782
1949 - 100762

1950 to 1962 Pre-Unit 500 & 650cc
Engine numbers had a prefix indicating the model type along the lines above such as 3T, 5T, 6T, T100, T110, 3TA, 5TA etc. This was followed by a number from the list below.

YEAR - Pre-Unit 500 & 650cc

1950 - From 100N
1951 - 101NA to 15808NA
1952 - 15809NA to 25000NA then 25000 to 32302
1953 - 32303 to 44134
1954 - 44135 to 56699
1955 - 56700 to 70929
1956 - 70930 to 82799 then 0100 to 0944
1957 - 0945 to 011115
1958 - 011116 to 020075
1959 - 020076 to 029363
1960 - 029364 to 030424 then D101 to D7726
1961 - D7727 to D15788
1962 - D15789 on

1963 to 1968 Unit 650cc
1963 - DU101 to DU5824
1964 - DU5825 to DU13374
1965 - DU13375 to DU24874
1966 - DU24875 to DU44393
1967 - DU44394 to DU66245
1968 - DU66246 to DU90282

1957 to 1968 Unit 350 & 500cc
1957 - H101 to H760
1958 - H761 to H5484
1959 - H5485 to H11511
1960 - H11512 to H18611
1961 - H18612 to H25251
1962 - H25252 to H29732
1963 - H29733 to H32464
1964 - H32465 to H35986
1965 - H35987 to H40527
1966 - H40528 to H49832
1967 - H49833 to H57082
1968 - H57083 to H67331

Frame number prefix :

Rigid - 3T = TC
Rigid - 5T, T100, 6T, TR5 = TF
Swing Arm - all pre-unit = S
Swing Arm - '21' = H