All pre-unit B & M singles had the notch in the frame to clear the oil pump. Since all were based on the pre-war M series, they retained that feature to the end.
All of the B series have the kink in the frame. Looks like you have a very early 1958 which will have the first alternator for electrics. That is a strange ‘F’!, but is what it should be.
The lack of a kink in the frame identifies the frame as having a Twin engine fitted.
Hi Wade----those are not very common in US--at least not in the north east IME.
I picked one up a few years ago in northern NJ.
It is a bit of a bitsa--the frame number is EB31 84** which I think means the frame is a 1956 or 1957---probably the latter.
The engine is GB33 5** which I think means it is a 1958.
It has alternator electrics and is fitted with a QPD primary belt drive.
I had a hell of a job getting an outer primary cover---one with the saucepan shape to cover the alternator--but eventually got one from Draganfly in UK.
HTH
All of the B series have the kink in the frame. Looks like you have a very early 1958 which will have the first alternator for electrics. That is a strange ‘F’!, but is what it should be.
It looks a bit like there wasn't an 'F' stamp available, requiring a bit of creativity.
The engine number is quite low and so is the frame number, so it would have been built very early in the model run. Wade will need aside trip at the BSA International to visit the VMCC library at Burton on Trent.
[quote=bsalloyd]
The engine number is quite low and so is the frame number, so it would have been built very early in the model run. Wade will need aside trip at the BSA International to visit the VMCC library at Burton on Trent.
So its quite possibly a matching engine and frame.... Previous owner wasnt sure but said its the pair that came to him..... Ill have to layout all the boxes to see whats there and whats not.... No fenders and no seat is all I know for sure at this point.
VMCC library sounds great
VMCC library sounds great

I'm a member, but you don't have to be to visit the library and go through the records.
I've already lined up a day there with my list of engine and frame numbers while Cheryl goes off doing touristy things.
The head librarian seems a rather nice woman, and has been very helpful so far.
From the dispatch book
"The numbers match, it was dispatched from The BSA factory on 30/11/1957 to Bsa inc (I think) which is East coast. It’s model is stated as B33B"
What does B33B mean?? Special trim ....base model..?
Started mocking up the bike tonight... Went from parts in a box to looking like a bike pretty quickly. Missing some stuff like headlight , seat , fenders and Ill need new rims as these are rusty but I am pretty happy overall ... Photos tomorrow ....
And why is there a distributor if its a Alternator model. And what attaches where the mag did ?
dizzy goes in the mag hole .
alternator charges a battery ... battery runs ignition and lights .
Thanks Quinten.... Im missing that cap on the primary cover too. Is that your bike...? Got a better photo showing the side stand lug. I seem to have the wrong one...
Any and all photos would be appreciated ... I work better from photos
Inner side stand lug coming my way from England.... A lucky find ... As long as its the right size .... Now I need to get the rest of the side stand...
i had '54 about 20 yrs ago and it cost me a small fortune to do.it was together,but missing about the same stuff as yours.it was my one and only b-33 experience.it probably had led a pretty hard life,but i'm not sure what is "normal' on those.mine had been used off road and was fairly thrashed. there were cracks in the case and the oil pump drive shaft that runs bushing-less in the case had worn the hell out of the case to the point that drive gear engagement was "iffy" at best. your lucky its not a magdyno unit as the dowels that register in the case had wallowed out the slots making proper gear alignment a drama.round dowel's in an aluminum slot are poor engineering after all the money spent and a definite lack of spares support (i was living in the u.s.) i swore i'd never own another. if i was driven to own another and just HAD to have one,i'd bite the bullet and buy an ABSAF motor,unless i knew where a truck load of spare parts are hidden as it was just totally worn out.i'm sure they have their adherants and advocates. i cut costs a bit by installing a belt drive, and while the down side it eliminated the cush drive,it wasnt going to be flogged anymore at least by me.pleasant to drive, UNPLEASANT to start,but it sure was a pretty thing!
Wade,
Rerminds me of my B50 which came in 3-4 boxes and a locked up motor. Had to mock it up just to see what was missing. I might do one again someday. It would have to be a big single, preferable a GS but they are not within easy reach anymore unless you your pockets flush with cash. Good luck with your project and thanks for posting all those pics. I found one of those up at Mid Ohio years ago but it was just missing too much for the price he was asking. I never understood why these bikes often have so many missing parts. Yours looks like most of it is there. Great find!
Mr Mike
Wade, It looks like they are denoting the main color after the model type. Some of the others on the list are marked "Blk" Looks like yours was entered by another person than normal, different handwriting. Might have thought that 'B' was enough to denote black,possibly a little lazy?
My tins are blue right now so If they are original .... I had not come to that conclusion yet... But I'll look closer .... Then blk as black and maybe "b" for blue??? Who knows ... I cant even read where mine was dispatched too.......
Those oil seal holders are a unique 1 year old only type, used on Unit twins, maybe unit singles also.
Mine look more like ones for B44s . as in these
https://www.ebay.com/itm/97-2514-NOS-BSA-FORK-SEAL-HOLDERS-CHROME-B44-C15-B25-T215-TROPHY-VICTOR-441/362952860099?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D225074%26meid%3Dfe831d54a3b34147b56a619b1a9ffc28%26pid%3D100675%26rk%3D1%26rkt%3D15%26mehot%3Dnone%26sd%3D133020462289%26itm%3D362952860099%26pmt%3D0%26noa%3D1%26pg%3D2380057%26brand%3DBSA&_trksid=p2380057.c100675.m4236&_trkparms=pageci%3A5a5b6328-978e-11ea-a9d6-aa33957dd1ba%7Cparentrq%3A1e370faf1720a4e8660c6855ffd55686%7Ciid%3A1
I should probably have these
https://thebonnevilleshop.com/bsa-a...fork-seal-holders-pn-29-5310-or-41-5142/
Got a pair on CBS .... Just so happen to be on sale and they are a Britbike sponsor ..... WIN WIN !!!!
My tins are blue right now so If they are original .... I had not come to that conclusion yet... But I'll look closer .... Then blk as black and maybe "b" for blue??? Who knows ... I cant even read where mine was dispatched too.......
There were only two distributors in the US at that time, East coast; BSA US Nutley, and West coast; Hap Alzina. So I would conclude it went to Alzina. I don't believe blue was a color available, only red or black depending on model. So again I would conclude black.
As for the STD 2, the 2 denotes that needle roller bearings were used on both shafts as opposed to bushings.
Bill B...
Hi Wade / Boomer,
As for the STD 2, the 2 denotes that needle roller bearings were used on both shafts as opposed to bushings.
I do not believe this is so, The needle roller boxes have "T" to denote Torrington needle roller bearing fitment
STD2 is a wide ratio gearbox fitted to US market Super Rockets (based on that I have never seen one over here)
The BSA gearbox data is in this BB thread,,
http://www.britbike.com/forums/ubbthreads.php?ubb=showflat&Number=15504I do not know how this wide ratio gearbox would work out on a B33 ?? Peter Quick did not seem to like it ??
John
Hi Wade / Boomer,
As for the STD 2, the 2 denotes that needle roller bearings were used on both shafts as opposed to bushings.
John
Okay, I was going by the difference between the RRT and RRT2 where the RRT has the rollers on one shaft and the RRT2 has rollers on both shafts.
Bill B...
The T2 denotes Torrington needle bearing in the "A" gear. These are only in two clusters (RR T2, SC T2). The STD 2 "A"gear is a 42-3088 with no needle bearing. Same as SC T, ARRT, ASC T,
So my B33 came with the STD 2 box but I also have the STD box as well. Which one would be better to use ? and why?
The T2 denotes Torrington needle bearing in the "A" gear. These are only in two clusters (RR T2, SC T2). The STD 2 "A"gear is a 42-3088 with no needle bearing. Same as SC T, ARRT, ASC T,
So what does it mean for the gearbox on my fathers A10 that has just T2 and no other letters?
Also does this mean that ALL the pre unit boxes were bushes layshafts? I was lead to believe that some had needle rollers there but could be an old wives tale
The T2 denotes Torrington needle bearing in the "A" gear. These are only in two clusters (RR T2, SC T2). The STD 2 "A"gear is a 42-3088 with no needle bearing. Same as SC T, ARRT, ASC T,
I disagree, the "T" denotes the needle roller on the layshaft, I believe it is in the blind hole. The "T2" denotes needle rollers on the layshaft end AND the "A" gear. In other words both (2) shafts.
Bill B...
So my B33 came with the STD 2 box but I also have the STD box as well. Which one would be better to use ? and why?
The STD gearing is probably more useful for general use. That was the STanDard gearbox used on most swingarm pre-unit A & B series BSAs. The others were for specific uses (TRIals, SCrambles, Road Race) so had different ratios. Who knows what they were thinking right at the end of the pre-unit manufacture?
Howdy Wade
That’s a great looking project you have
I have an early swing arm ‘54 B33 with a magdyno set up and std box
They’re a blast to ride
S
Wade: When I look at the complete chart for all the various gearboxes I see that the STD 2 uses the same layshaft as the STD box and thus will not have any needle bearings. A STD T box would have needles on the layshaft. The difference between the STD box and the STD 2 is that there is a different high gear pair of gears. The STD 2 has a 25/18 pair where as the STD has a 26/17 pair. These pairings change the overall ratio of the other gear pairs as they all go through the high gear pairing to drive the sprocket.
So with the boxes you have it would just be deciding on which ratios would be best for your type of riding.
Gordo
Hi All,
On the bottom right hand corner of the gearbox data sheet a table shows the ratios
ARRT, ASC, ASC.T and STD2 all share the same ratios, 2.877, 1.754, 1.325 and 1:1
There are more gear tooth differences than the A gears between STD2 and STD
T. gearboxes have needle roller bearings on both ends of the layshaft (do not confuse with TRI which is bush )
T2. gearboxes have another needle roller bearing in the A mainshaft gear (A)
Wade for normal road use fit the STD gearbox
John
Thanks All !! Good info!!
Howdy Wade
That’s a great looking project you have
I have an early swing arm ‘54 B33 with a magdyno set up and std box
They’re a blast to ride
S
One was loaned to me in New Zealand back in 2010 for the BSA Rally and fell in love with singles ..... One more cog in the obsession works.... I am looking forward to getting this on the road.... Although I have other things on the burner as well... Some closer to being runners then this one....
So as I am collecting parts and getting inspiration , I have pretty much decided to go with headlight fork ears instead of trying to find an original nacelle and the heavy fenders... call it the sportier American look I guess.... My question is for the fork ears. Will any of them fit my forks ? Are there differences in the years as far as fitment? Ill probably go with the same headlight that came on my 66 Spitfire with the dial switch since I have most of a spare one.
And with the click of a button I change my mind.... Who knows where this project will wind up.... a few beers last night and I am now (soon to be) the new owner of an original rear mudguard . Found it by accident because I was looking for the seat bracket and this popped up because it had the bracket I was looking for and others as well. plus tail light . Im pretty chuff but now I will have to find a front fender and then decide on Nacelle or not.... ??? I guess it all comes down to what becomes available.... Another trouble with the nacelle route is then I am locked into the correct speedo and switches and what not because they go in the tin work .... That could get crazy.....
I think any of the B, M, A series fork ears will work. The A65's are shorter between the triple tree.
Wade: From what I have seen the only A65 fork ears that will not work are those from the cranked down upper triple models. Most should work.
Gordo
Fender arrived from England. The rest of my parts from there are taking longer then this did ???? Hopefully not lost..... Now
I need the long curved brackets to mount this fender.... Its a 54 fender but mine being 58, Ive been told I will need to drill new holes for the brackets . I wonder if it matters which year brackets I get then????
![[Linked Image from i.postimg.cc]](https://i.postimg.cc/T2VkQhst/104089564-10160142579044012-312292873369882513-n.jpg)
![[Linked Image from i.postimg.cc]](https://i.postimg.cc/rsNQpY4B/104248467-10160142579079012-9146832530979961204-n.jpg)
![[Linked Image from i.postimg.cc]](https://i.postimg.cc/yY7LGs4s/104699226-10160142579174012-7843194364783195366-n.jpg)
58 is supposed to have the arrow head type bracket but I cant find a picture of a 58 bike with those on it? Late in the production maybe.....?
After two months of waiting for this lug to arrive from England I assumed it was lost in the postal black hole so I bought another one from America... Saturday they both arrived in the mail box... Now I have three since the american package contained two.... One a little smaller then the other.... The English one has threads in the holes and fits the frame well.... Thats probably the one I'll weld on... Is it worth trying to get it brazed on like the factory or welding is good enough?
![[Linked Image from i.postimg.cc]](https://i.postimg.cc/sDcHGcxs/IMG-7267.jpg)
![[Linked Image from i.postimg.cc]](https://i.postimg.cc/cCfjzGdn/IMG-7269.jpg)
Then I can paint or get the frame painted and start the actual build process. I try to be sure nothing else it missing on the frame first ....
Nice one Wade! If it was mine I’d grind 3 groves each side of the clamp, then spot mig the clamp to the frame at the point you have spot welded it (once you’ve found your happy with the angle and with it all still clamped together
You’ll be able to dress this up easily as opposed to a full bead of weld and once it’s clamped it won’t take much to ensure it never moves.
If you are going to weld it make sure you get as much of the brass off as possible. It will contaminate you weld if you do not. Lloyd L
Hi All
Why did BSA see fit to braze this in place on an otherwise all welded frame ?
They knew what they were doing, so I would follow suit
The frame tubing is quite thin and would easily burn through with arc weld
A65's with welded on side stands tear out the mountings
Pre unit BSA's with brazed stand lugs do not
2 cent opinion
John
Wade, You might want to do a little more research before you order the arrow head type for you fender (mudguard). I looked at two period shots of a 1958 B33 and both had the type held on with cap screws and nuts. The earliest I have seen the arrow head style was on a 1960 Super Rocket. I am sure the experts will chime in here. It doesn't sound like you are building a museum bike, so use what ever you have. Lloyd L
Arrow head stays for 60 on for A10’s so I would assume the singles were the same way.
Hi Wade.The B33 finished in 1960 (1959 for B31). Therefore they did not have arrow head stays, these were only on A7/A10 models.
That rear mudguard you have looks right for 1956-60. The flat in the beading on the edge is there for the flattened tube stays to pass over.
When buying stays be carefull with pattern items, a lot of them are made with the flat central to the tube. The rear edge of the flat should
be parralel with rear side of the tube.
regards, Pat A.
On rear fender stays you have to check length also. Goldstars came in three different lengths depending on fender style (English clubmans, US road bike or scrambler). I know you are building a B33 but lots of repro parts don't specify particular application and they all look the same. I personally do not like standard gear box ratios. They have a giant gap between 2nd and 3rd gear I find very inconvenient. I have heard the STD 2 is better.
Will an earlier front fender fit on my 58.... Like as in , one that says its for a 54-57? Has all the stays and all complete but whats the difference fit wise?
The one I found is pricey but there arent any others floating around it seems