Frame and ngine matching numbers. always?

[Atoll]

I have been told that BSA didn't always fit engines into frames with matching numbers. EG a 1958 A7SS with none matching numbers for both frame and engine. Is there any truth in this?

[duTch]

 Yep

 See chaterlea John's reply here;

https://www.a7a10.net/forum/index.php?topic=13217.0

https://www.britbike.com/bsapitstop/dating/ 

 **Edited (I think),  so disregard reply #4 & #6

[JulianS]

For our pre unit twins the term matched usually means that a particular engine and frame were despatched from the BSA factory as one motorbike.

The frame numbers for A series were series specific not specific to models in the series, ie for 1958 all twin frames had  FA7 prefix (or FA7A for Spitfire)

It is extremely unlikely that any engine and frame for A twins had the same production number (just the digits) after the prefix.

The only 1950s BSAs whic had the same production number engine and frame would have been GPO Bantams and AA M21s.

All change for mid 1966 season when frames gained a model identifier (for example A65L) and production number engine and frame would have matched less any prefix or suffix.

[Atoll]

For our pre unit twins the term matched usually means that a particular engine and frame were despatched from the BSA factory as one motorbike.

The frame numbers for A series were series specific not specific to models in the series, ie for 1958 all twin frames had  FA7 prefix (or FA7A for Spitfire)

It is extremely unlikely that any engine and frame for A twins had the same production number (just the digits) after the prefix.

The only 1950s BSAs whic had the same production number engine and frame would have been GPO Bantams and AA M21s.

All change for mid 1966 season when frames gained a model identifier (for example A65L) and production number engine and frame would have matched less any prefix or suffix.

Thanks Julian, just what I wantd to know.

[Atoll]

 Yep

 See charterlea John's reply here;

:https://www.a7a10.net/forum/index.php?topic=13217.0

https://www.britbike.com/bsapitstop/dating/ 

Sorry but the first link dos not work for me. 

[BSA_54A10]

For our pre unit twins the term matched usually means that a particular engine and frame were despatched from the BSA factory as one motorbike.

The frame numbers for A series were series specific not specific to models in the series, ie for 1958 all twin frames had  FA7 prefix (or FA7A for Spitfire)

It is extremely unlikely that any engine and frame for A twins had the same production number (just the digits) after the prefix.

The only 1950s BSAs whic had the same production number engine and frame would have been GPO Bantams and AA M21s.

All change for mid 1966 season when frames gained a model identifier (for example A65L) and production number engine and frame would have matched less any prefix or suffix.

Plus any special order contracts  like bikes for a police force or military contract
If you ordered 500 A 10's for your local police force those would be numbered 1 to 500

[duTch]

.......
    :https://www.a7a10.net/forum/index.php?topic=13217.0

  ......
Sorry but the first link dos not work for me. 

 Yeah- did it from the phone at the um cold drinks place....   Now edited and should function better than I ....had a cshitty colon at the start

[BSA_54A10]

Engines got the numbers stamped into them as they were made so if BSA made 1000 A10's they would be numbered 101 to 1100.
Then the tooling gets changed and they made 2000 A 7's these got numbered 1101 to 3100.
However the frames got made against orders cause frames are harder to store and the first order could have been for 50 A 7 and 50 A 10's
If the A 10's got made first and the storeman rotated the stock as he should the first 50 A 10's will have actual matching numbers but the first A 7 will be frame 51 with engine 1101 and from there on in no machine will have identical numbers on both engine & frame

[JulianS]

The only way to establish if your frame and engine numbers left the factory as one bike is a despatch book check via BSAOC or VMCC.