Wwii bsa...?

[MrIdiotFace]

I was hoping someone here could help identify this frame. I've looked at BSAs WWII era (just a guess) and I'm not finding anything that's a clear hit. And I'm not even sure this is a BSA. Any help is greatly appreciated. Thanks.

[Dougtheinternetannoyance123]

Yes, its a M20,, flat head BSA Preunit single. a regular BSA such as 350-500 thumpers will fit. B31, B33, B34 That was on FeeBay recently,, Did you buy it or are the seller?
What else do you need to know?
Until a few years ago Body work was near un-ob-tain-ium, but theres a ton of Indian made repop stuff out now cheap, Quality varies and expect to do some rework but its a god send that its even availible so best not to bitch. But Motor-Trans and related odds and sodds can be challenging to find. I got a bunch of these old bikes.

[MrIdiotFace]

Yes, its a M20,, flat head BSA Preunit single. a regular BSA such as 350-500 thumpers will fit. B31, B33, B34 That was on FeeBay recently,, Did you buy it or are the seller?
What else do you need to know?
Until a few years ago Body work was near un-ob-tain-ium, but theres a ton of Indian made repop stuff out now cheap, Quality varies and expect to do some rework but its a god send that its even availible so best not to bitch. But Motor-Trans and related odds and sodds can be challenging to find. I got a bunch of these old bikes.

Thank you so much for replying. I'm the potential buyer. The ask is 550. I've reached out to the seller to see if there are visible serial numbers but haven't heard back yet. Honestly, I know very little about the BSAs but saw this and my mind started working. I guess any resources you could point me to for this particular bike would be helpful. I really appreciate it. Thanks again.

[Dougtheinternetannoyance123]

Well, Its a mixed bad depending on many things. used to be this sort of thing had little value as most people were not interested in archaic old stuff like this. I personally LOVE the early styles,, 40s and 50s. But with a rigid frame Triumph going (40s-50s) for $800-1000 retail for just a decent frame other bikes start looking viable.
Putting a bike that together is do-able but challenging buying it piece by piece. There was a 48 or 49? Recently that allegedly sold for around a $1000 or so, there was a motor-trans-forks-wheels and odds and ends and much better deal IMHO..
This bike was local to me, I have met the seller before (I looked at a early Ariel he had) and while a little spendy most of it was there and could be a cool road bike with some work.
See: http://www.ebay.com/itm/1948-BSA-B33...vip=true&rt=nc

If you want to learn and follow some interesting tech, BritBike.com has some good tech and build threads. Used to be called BSA Pit Stop.
See: http://www.britbike.com/forums/ubbth...Board=1&page=1
600 pages of build and tech threads.

Basically,, back in the day BSA was THE largest manufacturer for bikes in the world. As they said,, 1 in 4 is a BSA. Everything from little 2 strokes and learner-kids bikes to full on competition bikes. But the meat and potatoes was every day go to work bikes back before people could afford cars in many parts of the world. The flat heads were produced for militarys and civilian use and up until the mid 1990s you could find NOS ones still in the crates for cheap. I have several friends who bought many of them and parts NOS Canadian military and were made up until mid 60s. Same with flat head Triumphs too. I have some of that stuff.
I collect BSA competition stuff and that was all specially hand built, Every competition bike was Dyno tested and I have some of the factory records including hand written notes. If a bike did not meet specs,, it was sent to a special shop for going back thru to find out why.
If you are interested in early BSA military bikes,, this story is interesting. A whole ship full of them sunk during the war and still lined up across the deck.

http://www.dailymail.co.uk/news/article-2702871/Treasure-trove-classic-cars-bottom-sea-The-British-Merchant-Navy-ship-carrying-military-vehicles-sunk-Red-Sea-Second-World-War.html

[Dougtheinternetannoyance123]

I was thinking about this will out in the shop looking at my own parts, For someone just kick'n the tires its not worth getting too worked up about all the tech, As I said, Go to the page above and theres 600 pages of BSA threads. You can spend years reading them all.
BUT...............
I will throw this out there. I love the style of those early rigid frames and I admit i looked at that frame online but IMHO its too expensive. If I could pick up that frame cheap enough I have enough parts to build a bike out because I am a Brit bike hoarder. I missed one just like it 2 years ago on a road trip in Calif for $250 that was nicer condition. (Pickup only and our schedules didnt line up)..
But here is what I am doing with something similar I have sitting on the shelf I have been collecting parts for several years. (Swap meets or online I have wish lists for multiple projects, when I see something i need I throw in the pile If I can get a good deal on it) So,, Like I said, building or restoring a bike like that with a bare frame would be difficult and expensive. I also hate seeing cool bikes being parted out but if you have orphan odds and ends its game on, and have some fun with it.
So, Let me tell you about the BSA M641 UAV. Its a mix of BSA parts and only BSA parts but basically a Johnny Cash bike. Its a mix of years and models. The frame is made up of BSA unit model 441-250 cradle and a C12 rigid Frame, Its got M20 Tank, oil bag and tool box. Fenders are repop M20. Motor is a 1966-7 BSA 441 Round barrell unit single. Every part IS BSA but from the 1940s to 1967. So the designation is a combination of M20-441 and UAV stands for
Urban Assault Vehicle in honor of the up-armored motorhome from the Bill Murray-Stripes Movie. When I was in the military we had worldwide mobility strike force I was in, and we had a Mobile command Post that was jokingly designated the UAV in honor of the movie.
A bare frame like the above COULD be used to build your own version. The idea is take parts sitting on a shelf somewhere, dont ruin a restorable bike but BUILD something cool and back out on the road. Thats something I like to support. Just saying.............

[Sky]

Did those frames even have numbers? Besides casting marks of course...
Any serial number would be on the cases. No such thing as a universal VIN back then

[Dougtheinternetannoyance123]

Many Did have a frame and model number. They made a M20 (500cc) and M21 (600cc), and keep in mind they actually made them into the 1960s as military contracs were lucrative. I would have to look up the dates but i have seen semi trucks packed with these in the crates and parts. I have pictures from an auction about 5 years ago of some Canadian stock.
See https://en.wikipedia.org/wiki/BSA_M20
Keep in mind also, the frames were nearly the same for the civilian B31/B32 and B33/B34 (350cc & 500cc) And I have a couple of those in both rigid and plunger frames so the only differences was the bottom frame rails were fully framed in on the Mil spec models (Note the tell tale BSA Single bulge on the bottom rail for the oil pumps)
but on the civilian spec models the motor is a stressed member. But the frames are identical other than that. So BSA was basically the General Motors of British bikes and MANY parts interchange but some do not. BSA also made a LOT of variations of stuff. For example,, the C10/C11 and C12s were small bore learner and commutter bikes with a similar style frame. They ALSO used the M series gear boxs but came in a 3 speed and used bushings where the heavier duty bikes used full bearings. Its easy to mis-ID the gear boxs and they would kind of fit, Priamrys off a C10-11-12 will work as well but the internals are different, Forks were early springers but later were hydraulic and I am sorting forks and triple trees right now for BSA and it gives me a head ache all the variations. I got parts books and hours of studying photos to ID them all..
But yes....... It SHOULD have a Frame ID and possibly a VIN, but not always.