Inner Primary Chaincase.

[Pilgrim]

    Can anyone out there tell me which is the correct inner primary case
for a '62 R.G.S.? The one on the bike is marked 42-7515 on the back
and 42-7503 on the inside and has the SHORT undrilled (no hole for a regular chaincase front bolt)
extension above the gearbox sprocket.
    I've also got a case that has the LONG undrilled  extension.
This is also marked with the same numbers? but, its the same as the case
fitted to the '63 which I believe to be correct. I'm thinking that BSA in their infinite wisdom
might have changed the spec. halfway through the production run, any ideas guys?
    To make it more confusing, I've also got a case, short extension but drilled
(for a  Super Rocket chaincase possibly?). That also has the same numbers cast into it.
Don't you just love Beezers! Much obliged for your thoughts on this.
    I'm now off to lie down in a darkened room somewhere!!!!

[chaterlea25]

Hi Pilgrim,
There has been some previous discussion on this topic !!
As far as I have been able to find out 42-7503 is the long type, so If you have a short one with tha same number thats a new variation to me?????? Has it been altered?

By the time BSA were making thr RGS, it was the end of line production, so I think/ have been led to believe that BSA fitted whatever components were to hand
BSA Dealers also swopped parts around to satisfy customers "requirements"
There was a dealer arrangement with the factory crediting the dealer for parts removed, against those fitted

HTH
John O R

[Pilgrim]

Hi John,
Thanks for the reply. Both of the undrilled cases show no signs of being altered.
    I asked the same questions to Steve Foden the RGS specialist at the BSAOC.
The reply was in much the same vein as your own. BSA seemed to use whatever came to hand
and after 50 odd years its not easy to check a lot of the production details.
    I just thought I'd throw the query up just in case there was a definitive answer out there!
I've just changed the gearbox sprocket oil seal and wasn't sure whether to refit the original (short) case,
or replace it with the extended case. The Pearson clutch came off fine with the A10 extractor by the way,
thanks again for that info. Cheers.

[trevinoz]

Geoff,
             I have probably said this before  but here goes.
The road test of the new RGS in '62 clearly shows the short inner case.
However, I have a long one on mine as does my '55 Flash.
I will fit a long one on the '54 RR, if it ever gets off the ground!

  Trev.

[Pilgrim]

Hiya,
Thanks for the replies guys.
I've decided to stick with the short version. It came with the bike
and the bike itself seems to be pretty much original spec. It would be nice to know if and
when they changed over to the long one, or as its been known before, did they just fit
whatever they found in the parts bins at the time!
Trying to attach a picture just out of interest. Titled GA10 943 2 TOURER. 

[trevinoz]

Geoff,
               Here's a couple from the 1962 road test.
Note the inner case and muffler!

  Trev.

[trevinoz]

Geoff,
                 This is mine after restoration back in the 80s.
It has the wrong rear guard and stays as the original was beyond repair and the number plate bracket is a pattern one which is not right.
The bike is lying derelict in the shed at the moment waiting restoration again and I have a new guard and tail light bracket to fit.

  Trev.

[Pilgrim]

Hi Trev,
Sounds like all you need now is time!
Thanks again.