First things first. My apologies for getting ahead of myself with the “Unknown Petrol Tank Markings” thread. I met Cas Vanderwoude on the Britbike forum and he immediately directed me to this website. I was anxious to start researching a bike that was not yet in my possession, but I didn't want to post photos of a bike that wasn't mine and possibly jinx the deal.

The quick backstory: a few weeks ago a friend of a friend tipped me off to a BSA WDM20 that was supposedly fairly intact and original. I’m a jeep guy (1945 Willys MB), but my heart skipped a beat, because I have always coveted a Beezer thumper. Even though I’m an American, neither Harleys or Indians are my style. My heart jumped when I saw the photos. Even to my untrained eye it looked virtually unmolested and legit. I shared some photos with Cas and Henk and they were kind enough to assess it and confirm my inexpert hunch.

Long story short, I picked it up and brought it home today.

Here are a couple photos.





And here is a link to many more photos - including some close-ups, in my photobucket album:

http://s1223.photobucket.com/user/Wingnut209/library/BSA%20WDM20?sort=4&page=1

As you can see, it’s also missing quite a lot, including the entire electrical system (I have the magneto) and the carb, also the throttle grip, the compression release assembly, foot controls, kickstart pedal, and lots of bolts. The tires are shot.

Thanks to Henk, I understand that the wartime tank number, based on the post-guard mudguard number (14YE73), would’ve been C5210625, and that this bike probably served in the BAOR after the war.

The VIN on the frame is WM20 99925. The VIN on the engine is WM20 27715.

The bike also bears a REME data tag with engine # 100163 and a 3-11-55 date stamp. I am assuming this is when it was last rebuilt?

All comments, tips, and suggestions welcome.

Nice acquisition. Keep us posted with your progress on it.

Thanks, btb, and will do.

Hi Duke,

Very nice and amazing they still come up in this condition.

Good luck with the rebuilt and don't touch the paint!

Cheers from the Netherlands.

email (option): m.wijbenga@hotmail.com

Thanks, Michiel.

It is amazing! As a jeep guy, I am used to dealing with rust, and cancerous rust. Cutting, patching, brazing and welding. The overcoat of green enamel this bike got in the late 1940's or so acted as a wonderful preservative. There is not a spot of rust. Also, it was in a barn under a canvas tarp for many years.

My inclination and sentiment right now is to preserve not restore.

Mechanically, I have seen no wear and tear on the internals so far. Perhaps the 288 miles on the speedo is accurate (although I realize that's a bit of a foolish pipe dream).

I have an M20 that came from the same REME shop in 1953. This shop was in Germany at that time. My bike also came to me in the untouched postwar green paint. It had "Drive on the right" painted in a V-shape across the top of the gas tank, just like yours-another sign it was used by British soldiers in Germany who were not accustomed to driving on the right.
You have an early "Fat" tank on your bike, with no cutout for the Vokes airfilter. Strangely enough, mine came the same way. Good luck with your restoration!

email (option): m20wc51@yahoo.com

That's not the early tank but the midwar 'non cut off' tank that superceded it...

Typically for a 'late service' M20 it is a mixture of parts from various years but is mainly mid war spec. One notable exception is the late war rear mudguard without the central rib...Ian

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

Our bikes sound like third cousins, doug! I am gathering that "WKSP" is short for "Workshop" and "4 BASE" identifies which one? Do you know where it was located in Germany?

Doug is the third person who has identified it as an early "Fat" tank, Ian, and you are the second person who has identified it as a later tank. I'm not saying that to pit anyone against anyone else or open a can of debate worms (I get enough of those on jeep forums!), but I would like to understand the differences.

I read in the "Historical Info/Facts" section about an early 3.5 gallon tank and a later 3 gallon tank, but there was no description or dimensions provided.

Without filling the dang thing up to see how much it takes, how can one distinguish them? How do they measure differently and where should I measure?

Complicating the issue for me is the knee grips issue. Which tank was being fitted with knee grips when they were discontinued due to the rubber shortage? My tank shows no signs of bondo where the fittings would be, so I am assuming it came after that, but I suppose I could be missing the spots under all the enamel.



I have the "Historical Info/Facts" section printed out, and I plan on going through my bike part by part to see if I can identify the mix, just out of curiosity. The headlamp, taillight, and horn are easy. Some of the other things (timing gear cover, filler cap, damper knob, etc) I have not yet inspected closely. For now, can you tell from my photos if my nearside center field stand is early or late? That's another one I'm not sure I understand.

Duke , are you down Florida way USA, if so your bike came from batch shipped over from Germany from war reserve stocks, , exported from Belgium, in the 70s, they all seem to have a pale green over spray over post war shiny green, I have one that I brought back from Florida three or five years ago, andrew

email (option): warbikes at gee male dot cmm, (think about this)

the early fat tanks are 3 1/2 imp gallon, these have the petrol cap hinged at the front and are very bulbous in appearance.
yours is the 3 gal mid service non cutaway..

email (option): chris dot astinbarker at bt internet dot com

Nice find mate!

I found this one in SanFrancisco a couple years ago which has some of the markings that are on your bike.

Regards,
Ben.

Andrew,

I am not in Florida and the bike was not in Florida, either. That doesn't mean much, though, of course, given the fact that it only weighs 400 lbs and will fit in the bed of a pick-up truck. It might have come out of that batch. The prior owner had a lot of wartime surplus and doesn't remember exactly where he purchased the bike or when, only that it was many years ago. It doesn't have a title, but he wasn't concerned about the results of the title/lien/VIN search that I will have to do to title it in my state of residence. Meaning, I doubt it ever had a title, and I suspect he was the first owner here in the US.

As for the colour, I'm glad you brought that up. If I describe what I have maybe it will help identify the bike's wartime history further, without having to wet sand the tank.

I'm not sure what you mean by "pale" overspray. The top coat of paint on my bike is a dark green that I would call moss green. There is not a trace of olive in it, as far as I can tell, but perhaps British OD shades are different than US. It may lighten up with a proper cleaning, but if I had to guess using the colours in the Tech Section here, I would call it Deep Bronze Green No. 24. The coat is very uneven, thick in places, and very thin in others, applied by hand with a brush. It is not flat. Either gloss or semi-gloss.

In the thin places I can see what looks like a layer of brighter green underneath. That layer, too, has no trace of olive in it. It is almost what I would call Kelly green. Again, if I had to take a SWAG, it looks closest to the Light Green G5 in the Tech Section here. And it is not flat either. It is gloss or semi-gloss.

This is the same color that is on several hard-to-reach places that did not get Private Snuffy Smythe's dark green gloppy top coat - such as the inside of the panniers frame and the underside of both front and rear mudguards. Those places have the exact same color as the places where I rubbed off the gloppy dark green top coat to read the frame and engine VINs. That brighter Kelly-like green layer seems to have been sprayed, not brushed. That color can be seen in some of my close-ups at the link above. Can anyone identify it as the wartime coat? It looks awfully bright to me.

Thanks. As Ian and Henk have told me. And my filler cap hinges at the back.

Thanks, Ben. Indeed, our bikes look like siblings. Yours is in even better condition than mine, I have to admit. Incredible! It looks to be a lighter shade of green, but I suspect that might change when I clean mine. I see your tank has the fittings for the knee grips. I'm going to have to check mine more thoroughly.

I look forward to trading more notes.

This confusion with fuel tanks stems largely from the fact that there is no standardised terminology or historic name for these components...as in so many areas of life, one man's 'fat' is anothers 'slimline'!

Early fuel tanks were based on the pre-war BSA style and were quite large externally but this was not reflected in the capacity as they had substantial cut-outs underneath to facilitate fitment above OHV engines. There was then a change over to a WD-specific more or less flat-bottomed tank and the overall size was reduced, giving a modest reduction in capacity but not nearly as much as might be expected, given the reduction in external size.

Many of the large fuel tanks sold pre-war were of the instrument panel (deLuxe)variety so were smaller capacity anyway.

I tend to think of these large early tanks as rather slab-sided, not bulbous at all, but someone seems to have coined the name 'balloon' tank and it has stuck. The later, smaller tank looks more rounded (and went on to give a silhouette to the post-war BSAs).

Your tank should have the threaded knee grip inserts, regardless of when it was made. Even when rubbers were deleted, they continued and were used as mountings for the tank-top air filters fitted in some theatres (and eventually to all of the last production models as they were intended for the continuing conflict in the Far East).

The British Army changed back to a gloss 'Bronze Green' after the war. This is lighter than most of the shades known as 'British Racing Green' (a touch more yellow) but still quite dark - To the best of my memory growing up in a garrison town, this continued until the adoption of NATO IRR green in the late 1970s. Any other colour is likely to have been applied after demob, perhaps to give a more wartime appearance along with the home-made blackout mask.

Incidentally, 'Series' Land-Rovers were delivered to both military and civilian customers in 'Bronze Green' through the 1960s and 1970s so the colour is well-known and widely available.

Thanks, Rik.


I suspect this is the color of the overcoat on mine.

But what do you make of the layer of bright, Kelly, almost lime green underneath that layer?



That green is the same color that is under the mudguards on my bike and on the inside of the pannier frame where the brush would not easily reach. That can't be a wartime color, can it?! It doesn't look like any of the colours displayed in the Technical Info section.

I've been going through photos of bikes to try to match this color to. Unfortunately, most of the WD bikes in the Rally photo section and the Visitor photo section have been restored. I did find one bike in the Visitors section that looks to be more or less in original condition that has a similar shade of green as the layer under my topcoat.

Cymon Charnley, Uganda


Thoughts?

Doug Price,

Disregard my request for the REME info. I just stumbled on your reply to a Denis J from San Francisco from a few years ago, who, like Ben Cameron (also from San Francisco!), you, and I, all seem to have bikes re-built around the same time at the same REME workshop, which I now know was located in Bad Oeynhausen. Thanks. Denis J's bike and my bike were re-built 2 months apart.

I took the tank off today to inspect it, and my curiosity got the better of me. I did a little light wet sanding with fine grit sandpaper to see if I could get down to the wartime layer of paint and expose any wartime markings. Unsuccessfully, I'm afraid.

Despite going slow and easy, I had terrible results on the offside.

I had better luck on the near side, revealing what looks like the remnants of a white C number, but I can't make heads or tails out of the numerals.



http://s1223.photobucket.com/user/Wingnut209/library/BSA%20WDM20/Petrol%20Tank%20Markings?sort=3&page=1

Sorry,Duke-I honestly didn't know there were three tank variations-I guess I learn something new every day! Here's my '44 from the 4 Base Workshop:

email (option): m20wc51@yahoo.com

Hi doug,

No problem.

Nice bike! What is the red marking on the oil tank?

I replaced the markings I found under layers of paint when I repainted it. There was a red "CP" on the oil tank. No idea what it signified.

email (option): m20wc51@yahoo.com

CP is usually the army acronym for 'Command Post' Ron

email (option): ronpier@talk21.com

hi Duke,
I like the tank as-is. Plenty character. Looking through the paint layers is like looking through time. Love it.

email (option): cas.vanderwoude@gmail.com

Perspective (or is it recall?) for everyone including Duke: All of these bikes were "rebuilt" by REME in the 50s, and they weren't shy about swapping an engine, tank, etc. Unless you know what REME did to your bike there is no way to "reverse engineer" the bike from such things as the shape of the tank, etc. The frame number is the only thing that can be relied on now to determine whether the bike is early, mid or late war. And remember that "preserving" in the case of these bikes means doing so as they appeared after they got worked over by REME, not as they originally left the factory or as they appeared during their intended (war) use. There are still some non-rebuilt bikes around, I think mostly in the middle-east, but yours is not one of them, in view of the REME tag.

email (option): jonny.rudge@verizon.net

Thanks, Cas. I plan to leave it as-is.

That is my understanding, John. What I aim to preserve is the entire history of the bike. As someone put it on another site: "She's earned her warts!" I was curious about the tank, but that' as far as I plan to go. Thanks.