My brother bought a WM20 in 1971 and I remember him saying the bloke that sold it to him said it was a 1952 model. My brother can't remember this but I am sure that's what he said on the day. Anyway the bike was painted green all over- now that's a surprise! and it had a nice green and chrome tank with this lovingly applied green coat of paint to match the rest of it. When my brother inspected the bike it wouldn't start so he suggested to the owner that checking the main jet might be an idea. The owner had bought the bike and was frightened of it- so it went in the shed it seems. Indeed, it appeared that the main jet was clogged- with green paint! After cleaning that out he started her up and bought her. The following year he got a holiday job building some kind of display for the Admiralty and went into various depots in Portsmouth where they still had M20s and he was given plenty of tips which did not include "get something more modern" which was heartening.
Anyway, as well as the tank the bike had a Dunlop Universal with a 1951 WD date, a control box with a 1952 date and an alloy head and a 376 carb all pointing to some kind of revamp in the 1950s ( or later) which ties in with the supposed date from the earlier owner. Indeed, the bike's civilian registration is 1965 so I was wondering if these alterations were done by the Army as opposed to a dealer after the event. The bike itself is in fact a 1942 frame and a 1944 engine and it also had a red GPO BSA Bantam throttle with the GPO roundel on it which I imagine some GPO Bantam fetishist would die for but I have put it somewhere exactly where I can't remember!
Anyway, I was wondering if the bike was beautified by the Army for some reason- or was this the work of a dealer or later owner? It's possible the Army wanted some more tanks and BSA sold them some chromed items but that is conjecture on my part. Quite frankly, it doesn't bother me if it is not all the Army's work as WM20s evolved but just as the Army acquired civilian M20s at the start of the War I wondered if the wheel turned full circle and civilian parts were bought post-1945 although you would have thought one thing the Army did not need was more spares for M20s! Back in the early 1970s it appeared every man that was 45+ had owned an M20 at some stage and they all had tales to tell- mostly uncharitable but Tony who lived over the road reckoned his red hot glowing exhaust pipe on his M20 was nearly as good as the light provided by the Prince of Darkness himself! Those were the days!

In OZ post WWII some MP's bikes got chrome tank, handlebars , headlamp rim & levers.
They also got shields ( sissys )

Latter the WD B40's used by the MP's look like they got he same treatment.

email (option): wariron@tpg.com.au

I assume the MP's bikes were new build machines rather than revamps of older models. I noticed that really woebegone M20 that was rescued from a seaside cave where it had been used as a winch for boats and restored by Jim in Australia had a chrome tank. I think that as a 1942 model so the tank was probably not original to the machine. I bought a brand new(old) chromed tank in 1974 for my M20 but when I got it home I found that the fixing lugs at the front are lower down and it does not fit. It must be for a telescopic forks fitted bike- probably a B31 although it could fit an M20 with teles I imagine. Another of life's big disappointments! The chap I bought it off was quite mad and he had worked for the council- he showed me some photos of his M20. He had sprayed the whole bike- apart from the front and back lights with white line road paint. He said he wore a white coat and a white skull cap helmet and gloves when he rode it and people thought he was a ghost! He was also selling a late 1940s Square Four but that was way out of my league- one cylinder was enough for me back then! Still is!

Hi Nick..The UK forces didn't get any 'newly manufactured' M20s after the end of the war. What was in service post war were all bikes from wartime production. Dates of registration, of course, could be from any year until about 1970 when the last bikes were disposed of....
It is most likely that the modifications were carried out after the bike came into civilian use. Post war spares were supplied in the correct finishes for military use and I have never heard of similar alterations carried out on a bike whilst 'in service'..Does the petrol tank have the large 'flip up' filler cap and twin taps?...Ian

email (option): ian@wright52.plus.com

In the classic motorcycle or classic bike was a article abouth an oficier who selected bikes for the army all cyvilian bikes there was olso a picture off it bud i can not remember wath year the magazine was. there ware triumph norton ohv etc.who were chozen by the officers and bougt from civilians maybe one of you will remember the article with that picture Gr Theo.Schipper

email (option): oldbikes@kpnmail.nl

saying that M20 were disposed of in 1970 i was stationed in cyprus till november 1972 and the squadron of the royal corp of transport there still had M20 on charge i wished i had taken more notice of them even a couple of photos would have been nice

The cap is a flat push and turn job and is definitely post-war with a single fuel line to the 376 carb. The tank is identical-except for the front lugs to the one I bought in 1974- and this new tank has a small plate inscribed AJN 1954 on it which adds more weight to the suggested 1952 revamp- the tyre with a late 1951 date, alloy head, 376 carb and chrome tank- although it is by no means conclusive. As I wrote earlier with all these parts the question is were they added after it was demobbed or before? The bike itself did not have a tool box- so no identification plate. From memory underneath the really tacky green top coat on the front mudguard I discerned P818 but you would expect TP 18- although I did not know that back then but I am sure it was P818- was this in fact TP 18 done twice badly, I wonder? The man that sold it reckoned it was a 1952 machine which is obviously not correct but I wondered if the Army reassembled it then and used a few new parts at that time and when it was sold out of service a dealer used this to suggest it was a more modern machine then it really was! I suppose we will never know but as I wrote above M20s were still being used by the military in Portsmouth in 1972. I do remember the Royal Marines in Portsmouth in the late 1960s had Triumph TRW bikes and I do not recall the M20s- and only noticed them after my brother bought his as that was when I became interested in old bikes. In 1972 I was given an ex-WD WW2 Enfield Bullet- complete with 1949 tax disc and 23 years of dust and in 1973 shelled out a whopping great £6 on an ex-AA 1959 M21- so my brother swapped his M20 for the luxury of teles and a plunger frame on my M21 which had been chopped to a degree. Also while I was away he also robbed my bike of its 376 carb and clutch and disappeared to Ireland where the M21 promptly blew up-it apparently had a standard piston in a +60 barrel and the piston disintegrated- so there is some justice in this world. Needless to say, I had to source a new barrel, valves and piston for him and get a new clutch for my bike which came from Russell Motors.The parts to rebuild the rubbish carb off the M21 came from closer to home as Amal parts were commonplace for this carb at the time.

Many M20s were reconitioned in the early to mid 50s for further service and as part of the rationalisation programme thet required a reduction of the number of vehicles overall after the war..Many of these carry the REME 'rebuild' plate with the post war registration number (as mine does) to record these rebuilds. To my knowledge all used the 'normal' WD M20 parts which were in abundant supply at the time as the Army still held huge stocks from the wartime period.....I think unless you can come up with a reason for these changes and/or some documentation to verify them as carried out by the Army it would be a massive and unlikely leap to assume this was done while the bike was still in service, as it would have been totally out of line with 'normal practice' and the usual parts employed at the time.(The monobloc carb wasn't even introduced until 1954 and to my knowledge has never been noted on an 'in service' M20) Far more likely that the bike was disposed of and altered subsequently by a dealer/owner before being registered. Many M20s were bought in quantity by surplus dealers and some must have stood in storage for considerable periods before they 'got round to them'. Also, you could buy an incomplete/non runner directly from these dealers at a knock down price and take it home and do what you liked to it before registering it......Ian

email (option): ian@wright52.plus.com

FWIW I have a 42 model ( photo in the gallery ).
It has matching numbers so is 99.9% certain to be a surplus sale.
It has an empire star chromed tank ( too long & thin ) & wheels.
Post WW II the now obsolete empire star tank was a whopping 10 shillings and the wheels were 2/6 each.
So for £ 10 ( purchase price ) +15 Shillings the owner could pretend he was doing well enough to buy a brand new bike rather than being a pauper on an army surplus bike.
Every thing else on the bike was black gloss over olive drab .
It also has a plunger hinged rear guard which being ribbed looks better on the bike than the "correct " flat one.
When I bought it it had been in continious registration since 1962 as the remains of the labels were all inside the label holder so I believe it is as it was when first registered so decided to leave it that way.

email (option): wariron@tpg.com.au

I think Ian (above your comment Trevor) is probably right that the mods are after being sold by the military but your comment about your bike getting an upgrade after WW2 is an interesting example. Mind you, swapping the rear mudguard although not difficult does involve removing a load of nuts and bolts which might be tricky. I am planning on doing this next year at some stage but will buy all replacement items as I imagine most will not be worth using again after removal- and that's before any drilling or chiseling is considered!
With the numbers of bikes involved and their careers after sale it is almost impossible to know what happened to a particular bike and that's often true of old bikes generally at a time when cash was scarce and bolting stuff on bought at a price was all that mattered. As Ian mentions the 376 appeared in 1954 and my bike has a spacer as well and I assume this makes starting when it is hot a little easier because the carb will not pick up the heat from the barrel. I assume these mods were made for good solid reasons as the bike was far from glamorous back in 1971- yucky green paint, exhaust pipe lacking any chrome or electroplating and a silencer not much better cosmetically. In fact apart from the tank it looked sad all over to paraphrase the pop song! It would be nice to have an inkling of its military career but that's just not possible and I think it is probably a case of a dealer making some improvements or an owner doing likewise with the carb and possibly the tank.
Looking at the photo of your bike it really belies its history as I would not have it as an WM20- all the chrome and the rear mudguard and carrier and would assume it was a civilian model which I suppose it is having left the military all those years ago and "gone up in the world" somewhat!

Just a little note on fitting a plunger guard.
You will either need to do a lot of redrilling or some "creative " stay work.
Note that the mid stay is not vertical as it should be.
I had to make some custom brackets to go under the saddle springs and match up to holes in the guard.
Also had to make up a custom oil tank mount bracket.
These were all missing when I got it.

email (option): wariron@tpg.com.au