The BSA A7-A10 Forum

Technical => Frame => Topic started by: shorty on 25.04. 2017 15:37

Title: a 10 frames
Post by: shorty on 25.04. 2017 15:37
Hi, my first post, Does the a10 rocket gold star have  an F a7 prefix to the frame number,?? or are they all  G A10 prefix,  the frame i am looking at has the lower cast engine lugs, i have no more info than this at the moment.thanks in advance for your replies.
Title: Re: a 10 frames
Post by: JulianS on 25.04. 2017 16:35
FA7 is an A7 or A10 frame from the 1958/59 season. If its got 4 lugs it is a later frame, maybe a factory replacement on for a crashed bike.

The RGS would have a GA10 frame number, all except the first 2 which had GA7 frames. See article written by Brian Pollitt and originally published in the BSAOC magazine, "The Star", in July 1996.

http://goldstarspitfires.weebly.com/uploads/1/1/7/0/11702298/brian_pollitt_article.pdf


 The 4 lugs dont make it an RGS frame.



If you have the Haynes A10 manual you can see an interesting frame, if you study the photos. Page 38 shows 4 lugs, a rod brake pivot (not in use) and a crossover brake shaft. This would be a universal factory replacement frame.


Title: Re: a 10 frames
Post by: shorty on 25.04. 2017 20:11
Thanks for your reply, very interesting article.
i think from bsa 0c list on internet the frame looks like it is a 1958 super rocket, i just didnt think that the super rockets had the 4 cast engine mount lugs on frame ?
Title: Re: a 10 frames
Post by: chaterlea25 on 25.04. 2017 20:26
Hi and Welcome Shorty *smile*
There are several other differences between the SR and RGS frames
A search on the forum will lead to several topics
Some export and maybe special order frames had the 4 lugs
It is also not unknown for frames to be modified *work*
Some decent  photos of the swingarm pivot area the battery platform brackets and the number stamping
should help sort out what it is

John
Title: Re: a 10 frames
Post by: shorty on 25.04. 2017 21:47
Thanks chatterlea, i have looked at various items on the forum and they show the swinging arm pivot with solid shaft for RGS and no side car mount,thanks for info, i will know more with a physical look at frame tomorrow.
Title: Re: a 10 frames
Post by: trevinoz on 25.04. 2017 22:16
GA7 frames with four cast lugs are not at all uncommon.
There are examples with the solid swinging arm spindle, notably those supplied to South Australia Police in about 1962.
Title: Re: a 10 frames
Post by: bob flashman on 26.04. 2017 23:25
Hi i have a question about A10 frames my fame has the no BA7 1870  with a engine no of DA10 9522 the bike is a 650 cc  swinging arm the V5C says the bike is from the year 1956 is this correct the reason for asking is i need a centre stand so need the right year.thanks for any help.


Title: Re: a 10 frames
Post by: JulianS on 27.04. 2017 09:02
BA7 is a rigid frame prefix.

You probably mean EA7 1870 which is a swinging arm frame number from 1956 season.

DA10 9522 is from the 1960 season.

Title: Re: a 10 frames
Post by: bob flashman on 27.04. 2017 16:21
Many thanks JulianS but the frame is a swinging arm frame and its stamped BA7 .The stamping looks to be original with the letters and numbers being the same size.
Title: Re: a 10 frames
Post by: JulianS on 27.04. 2017 17:08
Swinging arm frames were;

CA7 prefix for 1954 1955

EA7 prefix for 1956 1957

FA7 prefix for 1958 1959 and GA7 prefix for 1960 1963.

Link takes you to BSAOC year listings;

http://www.bsaownersclub.co.uk/yearlisting.html

For 1956 frame expect to see a hollow swinging arm spindle, on the offside a rear brake cable stop pointing straight back for hub lever pointing upwards and no sidecar mounting lug on the nearside pillion footrest frame loop (which featured on the 1958 on frames)

You could post a photo someone here should be able to advise.
Title: Re: a 10 frames
Post by: KiwiGF on 27.04. 2017 23:26
My bike is a 56 with pretty good provenance, it has what I thought was a side car mounting lug on the left pillion hoop, is this not the norm? Or is not a side car mount?

Pics attached.
Title: Re: a 10 frames
Post by: RichardL on 27.04. 2017 23:32
KiwiGF,

To me, what you have there is a frame left over from '55 production, as that is the brake pedal boss for a rod-pull brake. You do not have a side-car lug.

Richard L.
Title: Re: a 10 frames
Post by: trevinoz on 27.04. 2017 23:57
Kiwi, that is strange.
Can you fit your finger between the bottom of the battery tray mounting bracket and the cross tube?
Title: Re: a 10 frames
Post by: duTch on 28.04. 2017 00:56

 (Fairly sure)My Plunger A10 has a BA7 S 191** frame # , which I've decided is from '55/6.

 Just thinking that Swing Arm models before '57/8 may have been built workout sidecar lugs because Plunger frames were more suitable and produced up to '57...just guessin'...?    *dunno*
Title: Re: a 10 frames
Post by: KiwiGF on 28.04. 2017 03:24
Kiwi, that is strange.
Can you fit your finger between the bottom of the battery tray mounting bracket and the cross tube?

If am measuring this gap correctly nope, it's only about 1/4" enough for a pencil....as per attached pic

Title: Re: a 10 frames
Post by: KiwiGF on 28.04. 2017 03:29
KiwiGF,

To me, what you have there is a frame left over from '55 production, as that is the brake pedal boss for a rod-pull brake. You do not have a side-car lug.

Richard L.

According to the despatch records my bike left bsa in Dec 1955, so it's not a particularly early 56 model, but maybe they had lots of 55 frames left over and adapted them to be in the new Ariel hubbed (and cable rear braked) bikes *dunno*

Title: Re: a 10 frames
Post by: JulianS on 28.04. 2017 10:05
From what I can see in the photos the centre stand currently fitted is the one used on the 1954-1957 frames, part 42 4725. It fits between the mounting lugs.

Looking underneath , when bike is on stand that stand actually bears on the frame cross tube and the welded lugs would not take the later stand which bears on the lugs when bike on stand. This later stand fits outside the mounting lugs.

Going just by the number not letters and the photos your frame, they together, would make it early 1956 season, which would probably have left the factory in late 1955, 1956 frames starting at EA7 101 in September 1955. 

The side car mounting on the pillion loop was fitted to 1958/59  FA7 and 1960/63 GA7 frame.
Title: Re: a 10 frames
Post by: chaterlea25 on 28.04. 2017 21:20
Hi All,
Kiwi, does your bike have a steering lock?
It looks to be a gas welded frame?
I have wondered when they changed over to electric welded frames?
I have seem one that has a mix of weld types as if the sub assemblies were gas welded and the main frame arc welded??
Trouble remembering where I saw it now *red*
Was your bike originally exported to NZ ?
I think they were not too particular as to what was sent overseas ??

John
Title: Re: a 10 frames
Post by: KiwiGF on 28.04. 2017 22:30
Hi All,
Kiwi, does your bike have a steering lock?
It looks to be a gas welded frame?
I have wondered when they changed over to electric welded frames?
I have seem one that has a mix of weld types as if the sub assemblies were gas welded and the main frame arc welded??
Trouble remembering where I saw it now *red*
Was your bike originally exported to NZ ?
I think they were not too particular as to what was sent overseas ??
John

Hi John, yes it has a steering lock as per pic, I'm not sure if it's gas welded but attach a photo of a typical weld near the rear of the seat, I'm pretty sure but not positive my bike is "nz new" as it was delivered to a dealer in Liverpool that was known to do some exporting. I guess the kiwis got whatever bsa could cobble together!
Title: Re: a 10 frames
Post by: chaterlea25 on 29.04. 2017 00:38
Hi Kiwi,
Yes gas welded !

John

Title: Re: a 10 frames
Post by: trevinoz on 29.04. 2017 00:41
A couple of points.
I am fairly sure that electric welded frames started in 1957 along with the sidecar lug but were still EA7 frames.
It makes sense that it could be a CA type frame which was modified to become EA.