The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: bsa-bill on 11.06. 2020 12:38

Title: gearbox to standard
Post by: bsa-bill on 11.06. 2020 12:38
I have all the bits from a standard (Flash S/A) gearbox, my brother has a goldie and thinks he would prefer a standard box in it, just wondering if there are any reasons the standard bow internals would not fit into the Goldie box shell, bushes spring to mind
Title: Re: gearbox to standard
Post by: JulianS on 11.06. 2020 13:02
Use the Gold Star layshaft and thrust washers with the STD layshaft pinions.

The STD mainshaft and pinions should fit OK.

The RRT2 mainshaft will not fit the STD sleeve pinion.

Speedo will probably be a bit out using the RRT speedo gears.

Title: Re: gearbox to standard
Post by: bsa-bill on 11.06. 2020 13:25
Thanks, Jullian

Title: Re: gearbox to standard
Post by: berger on 11.06. 2020 14:11
bsa bill if it is just first gear that is a problem he could fit a 26t A65 layshaft gear and get a std box 17t gear turned down to make the shoulder that fits in the sandwich case next to the main shaft small ball race.  I have done this and even though it's a little bit taller than 16t and 27t it is better than 19t -24t rrt2 first gear
Title: Re: gearbox to standard
Post by: chaterlea25 on 11.06. 2020 18:55
Hi Bill,
As mentioned by Julian
DO NOT mix the Speedo gears
It is possible but not easy to swop the layshaft worm from one to the other

John
Title: Re: gearbox to standard
Post by: bsa-bill on 11.06. 2020 20:22
Thanks guys - I think it's going to be a bit more work than he wants to do and he was talking of the five speed option also, I just wondered as I have the std internals whether it would  be possible to just swap, but think I already suspected there would be more to it.

Once again many thanks