BSA Owners' Club Workshop Discussions

The BSA Workshop => Pre War => Topic started by: PaulGreen on 13 Sep, 2021, 08:41

Title: Please help me identify this fuel tank
Post by: PaulGreen on 13 Sep, 2021, 08:41
Hi all, this is my first post. Firstly, please forgive me if this is in the incorrect section - I am not certain whether the part in question is pre-war or not.

I have acquired a fantastic condition fuel tank... I am just uncertain as to what bike it belongs to, so I thought I'd consult the wisdom here!

The photos will give the best idea of the tank's features, but aspects which might help are the two bicycle pump mounts under the tank, the tapped knee-pad mounts and interestingly, the teardrop badges - which I had assumed were acrylic and had been painted over - actually transpire to me made from a ferrous metal.   

My mate's first thought was that it was maybe an M20, as the shape is very similar, but that would have had painted badges, we think???

After quite a bit of web research I am absolutely stumped - please, can anyone here shed any light on this?

Cheers,

Paul G
Title: Re: Please help me identify this fuel tank
Post by: PaulGreen on 13 Sep, 2021, 08:42
Two more pics -
Title: Re: Please help me identify this fuel tank
Post by: PaulGreen on 13 Sep, 2021, 08:53
Last one -
Title: Re: Please help me identify this fuel tank
Post by: Ian C on 13 Sep, 2021, 09:00
AFAIK this looks to be a post war M20 (Rigid or Plunger frame) tank that has been modified to take pear shaped badges, which were never fitted to these bikes. I've attached examples of badge types which would have been used by BSA.
Title: Re: Please help me identify this fuel tank
Post by: DAVE BRADY on 13 Sep, 2021, 09:16
Hi,

Someone has gone to a lot of trouble to fit pear shaped badges to this tank.  The badges themselves even look bespoke and I am sure that BSA never made ferrous badges of this type.  The underneath of the tank shows some welded/brazed on patches indicating that the tank has undergone some repairs.

Dave.
Title: Re: Please help me identify this fuel tank
Post by: idie on 13 Sep, 2021, 09:35
Certainly started life as an M20 tank. It has the link pipe at the front, as been said it looks as if someone went to a lot of trouble to fit the later badges.
Title: Re: Please help me identify this fuel tank
Post by: PaulGreen on 13 Sep, 2021, 10:02
Remarkable, isn't it, that someone would take that trouble (it has been done to a high standard). And manufacturing the accompanying metal badges....it just seems strange.

If it was indeed modified as described, could the patches on the underside be repairs to access points, that were opened up during the modification?

I'd love to know the story behind these modifications. Could it have been done at the factory? In terms of the timeline, might the very last M20s have overlapped with a period when teardrop badges were used, and someone wanted to mock one up?
Title: Re: Please help me identify this fuel tank
Post by: DAVE BRADY on 13 Sep, 2021, 10:51
Hi,

Who knows that BSA got up to but why use very carefully beaten out badges when the plastic ones were available?  Possibly this was pre plastic pear shaped badges and this was a trail and error process to get them right.  Another angle could be that stamped out metal badges may have been cheaper to make initially but finishing them to a high standard may have been more expensive compared to plastic ones.
Do you know if the plastic ones fit properly?

Dave.
Title: Re: Please help me identify this fuel tank
Post by: PaulGreen on 13 Sep, 2021, 11:06
This just gets stranger...

Have a close look at these metal badges. They have greater detail on the inside, than the outside. To me, the only reason for that would be if they were actually molds, perhaps for those rubber under-badges????  If so, who would have those molds, and why would they use them in place of badges on a modified tank?? Perhaps as temporary place holders to make sure the recesses are the correct size?? 
Title: Re: Please help me identify this fuel tank
Post by: PaulGreen on 13 Sep, 2021, 11:07
Oops, forgot the pic -
Title: Re: Please help me identify this fuel tank
Post by: PaulGreen on 13 Sep, 2021, 11:17
Quote from: DAVE BRADY on 13 Sep, 2021, 10:51

Do you know if the plastic ones fit properly?

Dave.

No, I don't have any to offer up. The metal 'badges' are roughly 128mm x 81mm at the widest part.
Title: Re: Please help me identify this fuel tank
Post by: Ian C on 13 Sep, 2021, 11:52
I own an M33 which is the M20 frame with the B33 OHV engine in it. It was sold to I believe Burma when new and it had modified 1968 on cast teardrop badge holes on it's original tank. So from that and seeing pictures of other bikes over there, I assume that owners wanted their bikes to look as contemporary models so tin bashed them to suit!!
Title: Re: Please help me identify this fuel tank
Post by: PaulGreen on 13 Sep, 2021, 12:17
Thanks Ian, a search for M33s eventually found this image. It's a 1952 model, apparently - not sure what country it was destined for.

Title: Re: Please help me identify this fuel tank
Post by: TJ on 13 Sep, 2021, 14:27
Could these metal badges actually be covers to protect the proper badges in transit? Just a thought, as the picture of the inside of the metal badge does not have the winged BSA letters on it.
Title: Re: Please help me identify this fuel tank
Post by: PaulGreen on 13 Sep, 2021, 14:55
Quote from: TJ on 13 Sep, 2021, 14:27
Could these metal badges actually be covers to protect the proper badges in transit? Just a thought, as the picture of the inside of the metal badge does not have the winged BSA letters on it.

That's not a bad thought - if fact they might have fitted the metal jobs over the rubber under-badges and just left them as tank protectors, only ever fitting the proper acrylic badges at the final dealer's shop??  The inside of the metal parts DOES match the shape of rubber under-badges. That would make sense, as I am learning, the acrylic badges (and the rubber knee pads) are not cheap items!!! 
Title: Re: Please help me identify this fuel tank
Post by: PaulGreen on 13 Sep, 2021, 14:56
I don't know their proper name, but these are what I am referring to as under-badges: