Is this an A7 or C model bike

[Jayce Lane]

Hi Guys

I tried to post this topic about 5 times last night and it bombed every time.  I have posted  a similar post with the C model forum.  so here goes....
I bought a BSA over the phone a week ago after the guy sent me a couple of photos over his cellphone.  However, after haggling on price and taking a closer look at it, I realised that it was not fitted with a standard bsa engine and exhaust.  Because the previous owner said it was a 250 I thought I might have gotten a C11.  however the guys on the C model forum are not entirely convinced that it is a C model as it has a cradle frame ie. two downpipes from the headstock to the engine.  Some suggested an A7, but if I look at the plunger frame particularly at the rear wheel, it does not look bulky enough for a a7 after looking at frame drawings on the internet.  Any opinions on this would be appreciated.  I also realise I have a long road ahead of me, but the journey starts out with trying to figure out what I have got....

Regards

Jayce

[Brian]

The frame etc is all C11G but the engine is a odd one. A two stroke of some kind.

[RichardL]

I am sorely sticking my neck out in an area I only know because I thought this was an interesting question and went looking for an an answer. Therefore, I am hesitant to disagree with Brian, but this does not appear to match pictures I found of C11s, such as the one attached. The gearbox is clearly different and there is just one downtube. I do agree that it certainly appears to be a two-cycle engine of some variety, but I couldn't nail down which one, without making it a career. I think this bike must be built on a A7 frame, but you could tell that in an instant with the number off the headstock.

Richard L.

[Brian]

The gearbox is the four speed one as fitted to the C11G's. Its possible the front half of the frame is from a A7 but I think more likely someone has been to work with a welder. When you get it you will be able to have a proper look.

[Jayce Lane]

Thanks Brian

That is the most definite answer that I have received from any one.  The twin downpipre from the headstock has thrown most of the guys I believe.  However I have myself have not found to much information out about the cradle frame for a C11g and frame drawings dont display the twin down pipe.  Any idea on year vintage...

Whilst responding I saw your answer Richard and welcome to my world.... Will hopefully get the bike this Friday and check on the headstock for the number.  My father inlaw has got it from the seller and has it at his place.  He could not find the number on the headstock, but his eyesight is not what it was and the bike has been covered in a primer.

Just saw your response Brian and hope to hell the welding job is not a reality.

Regards

Jayce

[RichardL]

In support of Brian's point, I suppose it's most unlikely that the C11 primary cover would have been sought out to use in an A7 hybridization. Brian probabaly knows several other reasons the C11 description fits. If it turns out to be a welded-on second downtube, that is some inspired analysis he's given.

Richard L

[Brian]

Here is a picture of what it should look like.

[RichardL]

Yes, I see the gearbox issue cleared up, for me. (I was looking at the relative locations of the filler/adjuster ovals.) That's a nice looking bike. Yours?

Richard L.

[Brian]

No its just a picture I found. I have had a lot of C11 and C10's over the years but then I came to my senses and got rid of them !!!!!

[Richard]

Just a thought but I think the A7/10 plunger frame is in two halfs front and back could this be an A7 front with the C11 rear end bolted up not welded?
Richard

[Beezageezauk]

Hi Jayce.  If I could add my thoughts on this one. 

From what I can gather all C10, C11, C11G and C12 models had a single downtube frame.  The frame you show has two downtubes but it appears to be a lightweight frame.  I'm sure the A7 frame is of much heavier construction.

It would help if you could find a frame number and post it for us to determine exactly what it is.

Beezageezauk.

[rocket man]

hi mate what you have there in my view is a bitsa a bit ove this a bit ove that myself i would keep clear ove it it looks like a lot ove hard work why not get an original c11 and do it up that way you will end up with a proper bike 

[Jayce Lane]

Hi Rocket Man

Would love to stop the sale, unfortunately have already bought the bike.  What happened was that I had only received the pictures of the left hand side of the bike, when I negotiated the sale and it is very unclear from those that there are twin downtubes.  The picture of the right hand side I only got after the purchase.  So I am in for it and have to make the best of it.  Will pick up the bike this Friday and will attempt to find the frame number.

Richard if you are right, then I might have two halfs of a bike, I suppose I can chose which way to go either a7 or c11.  Novel concept.  Its like having a combination New VW beetle at the front and old VW at the back.

Regards

Jayce

[fido]

I would suspect the only BSA part is the tank, which looks too big for the rest of the machine. I hope it was cheap 

[Jayce Lane]

Fido

Interesting observation the thought has passed my mind.  An Ariel 200cc from the same era has a very similar back end.  Cheap is relative but I picked up for 200 pounds rougly converted.

Regards

Jayce