The BSA A7-A10 Forum

Technical => Frame => Topic started by: a101960 on 13.03. 2010 11:12

Title: Centre stands
Post by: a101960 on 13.03. 2010 11:12
Swinging arm centre stands: Has anyone got any idea how many different variations of centre stand widths there are? I have just purchased one and it is to narrow between the lugs on the stand itself to fit the frame lugs. The discrepancy is roughly equal to the actual width of one frame lug that is to say about an 1/8th of an inch. I assume that this can be rectified by removing 1/16th off of both side of the stand lugs. Before I do this, is there another stand that will go straight on? Looking at the parts book I can only see one number but that does not mean that there is not more than one width. I am extremely puzzled!

John
Title: Re: Centre stands
Post by: flashblack on 13.03. 2010 18:34
Hi John, I`ve just measured mine, and the lugs are just under 4 1/4" (outside edge to outside edge), and the stand is 4 1/4" (inside to inside) . The stand, i bought from c&d auto`s a few years ago, and is one with no kick leg (for a siamese system) Hope that helps Rich. 
Title: Re: Centre stands
Post by: a101960 on 13.03. 2010 19:52
That is a very interesting picture. My frame lugs do not look like yours. Thanks for that.

John
Title: Re: Centre stands
Post by: alanp on 13.03. 2010 20:15
John, if your lugs are different to Rich's then your frame sounds like an older frame which uses the frame cross tube adjacent to the lugs as stop positions for up and down. The later type which Rich has uses extra lugs to provide the up and down stop positions and fits outside the frame lugs. Your stand is (should be) cast differently and fits inside the two lugs with a width over the stand casting of about 4". I don't recall at which year this changed. I had one like that on my Gold Star.
Alan.
Title: Re: Centre stands
Post by: a101960 on 13.03. 2010 20:33
The plot thickens! So it is a Goldie type centre stand that I need. The odd thing is my bike was registered in1960, and that was when the later stand was supposed to have been fitted from. Having said that, just because it was registered in 1960 that in itself does not rule out the fact that it might have been an earlier build than that. There is another little curiosity. The front engine mount lugs are the same as an RGS. After all this time who knows what it might be!

John
Title: Re: Centre stands
Post by: alanp on 14.03. 2010 11:58
RGS front lugs are 4 wrap around type, i.e. the bottom 2 are the same as the upper 2. Is that what you've got?
Alan
Title: Re: Centre stands
Post by: trevinoz on 14.03. 2010 20:32
Four cast lugs on the front tubes are not exclusively RGS.
Trev.
Title: Re: Centre stands
Post by: cus on 14.03. 2010 22:06
G'day John,
You would have "GA10" prefix if it was RGS frame.

regards, Cus
Title: Re: Centre stands
Post by: alanp on 15.03. 2010 08:55
Trev, that's interesting, what other models had 4 cast front lugs?
Alan
Title: Re: Centre stands
Post by: a101960 on 15.03. 2010 19:35
Quote
G'day John,
You would have "GA10" prefix if it was RGS frame.
The frame is CA7 so the RGS frame wrap round engine mounting lugs identification marker is it would seem just another urban myth! I know that my frame is not an RGS frame but I am curious about the wrap round lugs. Open a can of worms and you find a lot more worms in the can than you think there would be. Anyway my frame stand lugs measure 4 and 1/2" outside to outside. It looks like the stand that I purchased is correct but slightly under sized. I am going to get 1/16" machined off both sides to make it fit. All very odd though.
Title: Re: Centre stands
Post by: cus on 15.03. 2010 20:44
John,
My bike is a 61 S/R, but has the four lugs, my frame had been cracked on one of the lower lugs in
a previous life, the bike was used as a hill climber, & someone had welded it back up & added the
bracing lugs. It wasn't a good job, so I had it professionally done & now looks very close to the
top (standard) lugs. I'm sure there are quite a few frames with this mod., not saying that yours
is one, but those lugs, if factory fitted have a raised code on them.

regards, Cus
Title: Re: Centre stands
Post by: trevinoz on 15.03. 2010 20:52
John,
          Your frame is surely GA7, not CA7?

Alan,
         You will find that all frames from around 1961/62 have four cast lugs. In my experience anyway.
I will be interested to hear from other members on this.
Trev.
Title: Re: Centre stands
Post by: a101960 on 15.03. 2010 22:05
The frame is stamped CA7 and it started life as a Shooting Star. It could be that the stamp has been partially filled in by paint. It has the rod operated back brake. Isn't it amazing where a simple question about something like a centre stand can lead to? My bike is a bitza for sure and I am not making any claims to an exotic ancestry. It is just a case of the more I find out the less I seem to know. There so many A10's about that superficially look the same until you start looking closely at them. I have heard it said that BSA were not averse to mixing and matching from the parts bin to keep the production line going. Add in the equation of previous owner mods that were resorted to in by gone days to keep the bike on the road and it gets hard to know just exactly what you have got.

John
Title: Re: Centre stands
Post by: chaterlea25 on 15.03. 2010 22:31
Hi, trevinoz
I have a hunch that the 4 lug frames were export (Australia) only???
Maybe BSA anticipated a rougher life out there???
On this side of the World the 4 lug frames are a rarity and I have only
come across them on supposed RGS's as well as genuine ones!!
Regards
John  O R
Title: Re: Centre stands
Post by: Beezageezauk on 16.03. 2010 09:56
Hi John,

Here is a quote from Roy Bacon's book "BSA Twin Restoration".

The pivoted fork (swinging arm) frame introduced in 1954 had it's own form of Centre Stand with the feet shaped to assist the lifting of the machine, it's spring fitted on the right and a toe peg on the left.  It's feet were changed for 1958 when they took on a more "Oval Form", and again in 1960 when the spring moved over to the left hand side.  A second stand appeared in 1960 (without the toe peg) specifically for the "Spitfire" model.  In 1962 this stand was used on the "Rocket Gold Stars".

You mention that your frame number began with CA7****!!  This series of numbers were for the 1954 and 1955 models only and this could explain why the later stand won't fit your frame.

If I remember correctly the earlier stands were of a more rounded construction towards the top and the 1958 on stands were more like a conventional H-section. 

Check your frame to see which side the spring retaining lug is on because if you were to open up your stand to fit the spring could be on the wrong side.  However, this could be easily rectified.

Beezageezauk.

     
Title: Re: Centre stands
Post by: trevinoz on 16.03. 2010 20:18
John,
            The CA7 frame should have the so called "Goldie" type of stand. It mounts with a stud and nuts which sandwich a tube between the lugs on which the stand pivots.

John O R
             Possibly you are correct in your theory.
The four lugs were used on US bikes for sure as well as the few that seem to have landed here at that time.
The South Australian Police bikes had four lugs as well as a QD crinkle type hub on the rear, full width front.
Trev.
Title: Re: Centre stands
Post by: a101960 on 16.03. 2010 20:45
Trev,

And also everybody else thanks for all the information. The stand is now in the hands of Station Workshops where it is going to be machined to fit. Now, I know you are all going to tell me different, but all the suppliers of BSA parts that had stands in stock told me that the earlier stand is unobtainium. The good news is that there is plenty of meat on the stand lugs and that it can be machined to size without compromising the structural integrity. Nothing is ever straight forward is it?

John