Frame/engine number match...

[Padsta33]

Maybe a dumb questions but are matching numbers of frame and engine just that...matching? Or do certain engines match certain frames?
Confused....

[bsa-bill]

they do not match for A10/7 (later A50/65 do I believe)
often when the term matching numbers is used for our A's it means the frame number and engine number match in as much as they were produced in the same year, lists of frame and engine numbers do exists, if no one else put them up I think I have then somewhere - will look later

[duTch]

 My limited knowledge of this is the Engine number and Frame numbers are not the same but match with regard to factory despatch records until numbers with ?A******, up to late Pre-unit A series that became GA****s


 B-Bill rounded me up

[muskrat]

Here's a good list of all BSA's  http://www.britbike.com/bsapitstop/dating/
Cheers

[Padsta33]

Here's a good list of all BSA's  http://www.britbike.com/bsapitstop/dating/
Cheers

Cheers Muskrat,  that's pretty comprehensive!
Would my 1957 a10 standard have same prefixes as the Swingarm goldflash? 

[muskrat]

The 1957 plunger had engine # BA10-16036 ^, frame # BA7S-20289 ^.
The 1957 swing arms were either Gold Flash or Road Rocket. GF engine CA10-, RR CA10R-, both EA7- frames.
Cheers

[Padsta33]

The 1957 plunger had engine # BA10-16036 ^, frame # BA7S-20289 ^.
The 1957 swing arms were either Gold Flash or Road Rocket. GF engine CA10-, RR CA10R-, both EA7- frames.
Cheers

Brilliant!
That puts me in the "matching number club" then.
Great info...Cheers.
Paddy

[KiwiGF]

Well there are 2 definitions for matching numbers then, I'm not sure why some buyers will pay more for a bike that has the paired numbers it left the factory with but to avoid any misunderstanding should you ever sell the bike I would make it clear whether the numbers are just of the same year or whether they are paired as they left the factory.

Technically my bike has matching numbers paired as they left the factory, but the (unnumbered) timing side crankcase is actually off another bike due to past crankshaft blow up (I actually have the case but it's in door stop condition). That underlines the fact that a paired numbered bike may only comprise the original frame and left hand crank case and the rest of the bike could be a collection of parts.

The engine number is the primary way BSA indicated the model (a7, golden flash, road rocket, super rocket etc), and is also the order/sequence the bikes were despached date wise (and in the original BSA despatch records) I'm reliably told, so it's easier to find the frame number that was fitted to an engine than vice versa.

[tommo903]

Hi,
I'm a new member to this forum and seeing this question has prompted me to ask my own. I'm looking to buy an A7SS and I'm wondering is someone can tell me if this particular frame and engine left the factory together...
Frame  CA7-12797
Engine  CA7SS-1881
Im reasonably sure both are 1955 but the numbers looked too far apart to me to have left together.
Would appreciate any thoughts...thanks.
Steve

[RichardL]

It does appear that they are both '55. They would not be matching numbers and the distance between numbers is not a concern, as long as they fit within the ranges shown on the list. Barring numbers being tossed out, the frame would be the 5,296th built for '55 and the engine the 1,380th of its type. This makes sense, since the same frame was used for several different models. All this said, the only way to know if they left the factory together is to get the dispatch report from BSAOCUK. Go to their website and follow the instructions for getting a dating certificate.

Richard L.

[RichardL]

Well, the path to finding the dating certificate application form is not completely obvious, so here it is:

http://www.bsaownersclub.co.uk/machine_dating/BSADCVR_request.pdf

Richard L.

[RichardL]

Oh, I almost forgot, "Welcome to the forum." An intro post telling a bit how you came to have your A7, or interest in bikes in general is always appreciated. Also, if you feel like it, we all love pics of bikes in all states of repair or finish. Finally, a little insight to approximately where you are located can sometimes help in giving (or getting) local information for parts, services and events.

Richard L.

[tommo903]

Richard,
Thanks for your replies...they were very helpful!
I asked about the particular frame and engine nos as it was a bike that I went to see yesterday with a view to buying it. The owner had a copy of the original 1955 registration document which showed the same nos. so I now feel pretty certain that both frame and engine left the factory together. My only concern was that I couldn't actually read the frame no. on the bike as it had been powder coated some years ago...not something I particularly like. Anyway, I've taken a chance and bought it...it's one of those bikes that the owner has had for 10 years and also knew its whereabouts for the previous 20 odd years, so I have a reasonably good feeling about it. In fact, it seems not to have moved out of a 10 mile radius from the original dealer who sold it in 1955.
This is the first BSA twin I have ever owned but the second BSA (I've had a Starfire for 20 years) so I will no doubt be needing lots of help on this forum. By the way, I'm located in Buckinghamshire in the UK

Steve

[duTch]

Here's a good list of all BSA's  http://www.britbike.com/bsapitstop/dating/

 I've seen this link a few times but couldn't remember where I saved the link, so picked a random one as it's mentioned in a few posts....

While checking for where my frame # fits in the sequence I just need to satisfy my curiousity  that there are no A7 Plunger models listed after 1954, so presume they were (quite logically) discontinued thereafter...is that correct ??

 This more specific ; https://www.britbike.com/bsapitstop/dating/1951-60.html

 ( For what it's worth, as far as I can tell with crossed-eyes, my BA7S 1919* is 500 short of the tally of 19698 for the '57 year run so I guess I'd say was stamped around May-June '57 ?? ). That makes it one of the most modern Plunger A10's, with a tried and true '52/3 engine...so with its engine specs, I can almost be quite justified in calling it an 'early Rocket'    ? )
                     

[JulianS]

From Glass's Motor Cycle check book showing last A10 plunger frame and engine number in July 1957.