All heavyweight models except the '39 T100 and all 1940 models used the same tank, a 3 1/4 gallon tank easily recognised by the asymmetrical concave recess underneath for the 500cc single valve gear. Only one small change occurred, the addition of tank badge screws for 1938, '37 models having decals (transfers) for the badges. Tanks were always chrome-plated with three painted panels. The T100 had the first of the larger 4 gallon tanks and this coincided with a different front fork setup resulting in a different headstock angle on the frame. The larger 4 gallon tank will foul the steering lock on the earlier TH prefixed frame. For 1940 all models got the new TF frame and therefore the larger tank as well. Tank badges changed again in '39 from brass in '38 to an alloy material as the post-war variety.

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. It has a semi-matt quality and no sign of brushstrokes unlike many modern efforts with gloss paint.

The rear mudguard came in two widths (not including the optional valanced guard). As a general rule the wider, 6'' guard was fitted to all models except the Tiger 90 which sported the narrower 5'' job. It has to be remembered that at that time narrow mudguards and high pipes were regarded as sporty and as such appeared on the tuned models. For that reason the Tiger 100 seemed to have been supplied with the 5'' rear guard unless the larger, 6'' was specified.

The front mudguard, again, came in two sizes. A 5'' width, usually found on the Speedtwin and Tigers, and the deeper, 6'' width usually found on the deluxe range. This 6" front has indents either side to accommodate the fork legs. I have indicated which mudguards came with which models but all were optional and could be changed around. In addition, Triumph offered a pair of heavily valanced mudguards as an optional extra. These were based on the 6'' guards front and back but included a welded section down either side. Very rare now but I have seen a pair.

It should also be remembered that the front numberplate mounting changed for '39 so front guards are specific to the year. 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 Speedtwin 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, others a brighter, mid-blue stripe which appeared on the mudguard, edging the black centre rib. The latter arrangement particularly on the '39 Tiger 100.

As explained in the introduction, the rules for paint colour finishes are not hard and fast. They do, however, represent the large majority. Most accept that Tigers are silver, speedtwins are red and so on. The buying public were conservative at the time and the arrival of the speedtwin in amaranth red with gold lining was probably seen as quite flamboyant. It's not surprising then that some customers did request their speedtwins in black and there are several well-documented cases. I have spoken to one elderly ex-owner and seen photographs of his new black speedtwin so am quite satisfied it occurred. It probably cost more to produce the red finish anyway and with black machines (6S, 5H etc.) being produced alongside it's not surprising that Triumph were quite happy to supply the more utilitarian colour.

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 Speedtwin 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, front brake arm spring and the Lucas DC40.

1937
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.

1938
Tiger models: As 1937

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.

1939
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.

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.

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 the high 'mirror' gloss favoured by many. 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 Speedtwins 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'.

In order to understand the many variations in colour and detail specification it has to be remembered that many customers bought directly from the works. With the factory as a point of purchase it was a relatively simple matter to tailor individual models to customer requirements. This was, after all, still the age in which customers were treated as a valuable resource rather than the prescribed 'take it or leave it' process we have become accustomed to.