The BSA A7-A10 Forum

Technical => Frame => Topic started by: Gonemad on 25.03. 2012 19:29

Title: RGS silencer - swinging arm clash
Post by: Gonemad on 25.03. 2012 19:29
My RGS replica has the correct narrow crinkle Q/R hub, in the donor Super Rocket frame, the wheel spindle of which impacts the silencer, or would do if I let it.  The silencer that came with the bike had a dent in it where the offside rear of the swinging arm had impacted it so I bought a nice shiny new silencer with a longer fixing bracket, that'd be silencer to frame via the rear footrest. If the new silencer had an even longer bracket the silencer would point down. If I put a spacer in between the bracket and the frame the footrest stud would not be long enough to get a nut on and the silencer would point outwards.
An answer would be to shorten the rear wheel spindle at the part where it has two holes for a toggle bar to undo it for removal of the wheel by turning it shorter in a lathe and removing one of the holes. A better solution would be to make up a new spindle with a hexagon end for a spanner. The new spindle could then have an end of, say, about 10mm long instead of the long, about 30mm, two hole round end.
Am I making my self clear?  I can attach a photograph if it would help.
Is it possible that I have got the wrong spindle?
Any thoughts guys?
Title: Re: RGS silencer - swinging arm clash
Post by: Pilgrim on 25.03. 2012 21:32
Just a thought, what length are your shocks? If they are too long they might allow
the swinging arm to drop down too low giving you the problem.
I measured mine at 12 & 7/8ths inches between mounting centres.
My spindle only just misses the silencer by about 1/16".
Title: Re: RGS silencer - swinging arm clash
Post by: trevinoz on 25.03. 2012 22:15
Here's the exhaust on my sad RGS plus the similar set up on my Super Rocket.
The RGS siamese pipes are a pattern set which I fitted probably 40 years ago. They were never satisfactory in fit and when I restored the bike in 1985, I modified them for a better fit and fitted a Goldie muffler, which was not fitted from new.
The exhaust clears everything but the spindle will not come out with the muffler in place.
The Super Rocket exhaust is a siamese, same as original RGS and fitted to some US export machines.
The pipes were made locally and are a very good fit, the muffler is a copy of the RGS type originally fitted to my bike.
I have another set to fit to the RGS when I get around to doing it up again.

Title: Re: RGS silencer - swinging arm clash
Post by: Gonemad on 04.04. 2012 15:30
Sorry for the slow response Pilgrim. I thought that you might be onto something when I measured my rear shock absorbers and found them the 13 -3/8? centre to centre as compared to your 12 ? 7/8ths?. That is half an inch which would make a considerable difference.
However, Trev?s bike looks pretty original and has about the same clearance as mine.
Since I plan to sell the bike, un-ridden in order that it retains its showroom appearance, I will put the old dented silencer on it just to run it around the car park to ensure that all is in order for an MOT, re-fit the brand new silencer and call it a day at that.
Thanks for the replies boys.  The photographs were very good.