Swinging arm upper possition ??

[Viking]

The BSA A frame, swing arm type, has two possible mounting positions for the swinging arm, where the swinging arm spindle is fitted-pivot point.

Upper or lower position.

What is the upper position for ?

I have never seen a BSA bike where the upper position was used.
Is it for scramblers ?  Special racing or ????

Why is the frame made this way ?
It is for B type or ??

or just for "kicks"

[1660bob]

Hi Viking, I do not think the upper holes are for swingarm mounting.In fact I think they are too small(for the hollow spindle at least) and too close to the frame tube/weld to  accept a nut washer?. I have noted that on some (Goldstar?)models, the upper hole on the drive side of the bike gives access to the chainguard front bolt to allow removal.
I agree they seem to be a bit of a mystery, a bit like the tab with two holes that protrudes rearward from the lower rear engine mount, it seems BSA had something in mind when they included this on the frame, but I have no idea..... Anyone else know? Bob C.

[bsa-bill]

a bit like the tab with two holes that protrudes rearward from the lower rear engine mount

IF! it is the tab I think you mean then it holds a bracket that holds the bottom of some rear mudguards

[Klaus]

I agree they seem to be a bit of a mystery, a bit like the tab with two holes that protrudes rearward from the lower rear engine mount, it seems BSA had something in mind when they included this on the frame, but I have no idea..... Anyone else know? Bob C.

Save some wight 

I gues this upper holes where needed to fix the frame at the assembly track.

https://www.youtube.com/watch?v=XwjubHY2A4s

cheers Klaus

[trevinoz]

Bob has it right, it is an access hole for the front chainguard bolt on '54/5  frames along with RGS & GS.
The "tab" is for the bottom bracket attachment on '54/5 & RGS rear mudguards.