The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: Rocket Racer on 13.10. 2009 21:54

Title: 1956/58 alloy rear hub axle diameters
Post by: Rocket Racer on 13.10. 2009 21:54

I have one of the ariel/bsa type alloy full width rear hubs going into a special I am building, the main axle is an inch (hollow section), but the stub axle on the sprocket side has a flat machined into it of .508" diameter which does not appear an original dimension.
Can anyone confirm the diameter that the slot in the swing arm on the sprocket side should be for an alloy rear hub type frame -
as distinct from on the brake side (being an inch).

In my case the hub is going into a rigid replica frame and it would be nice to maintain standard BSA dimensions where possible although these frames were typically built with the splined QD type hubs which are not as robust for side car race loads.

Title: Re: 1956/58 alloy rear hub axle diameters
Post by: minibsa on 15.10. 2009 12:02

   As I recall the sprocket side on a 56 is the same size as 58 on, but the stub axle is different. I remember considering machining the drum side of a 58 swing arm to fit the alloy hub because I couldnt find a 56 swing arm some time back . (58s are more plentiful).
cheers    Bob.

Title: Re: 1956/58 alloy rear hub axle diameters
Post by: muskrat on 15.10. 2009 12:13

G'day RR, just pulled the wheel out today. 11/16" is the size of my '57.
What is the other hub in pic ?
Cheers

Title: Re: 1956/58 alloy rear hub axle diameters
Post by: Rocket Racer on 16.10. 2009 04:53

thanks for the diameter, we've stuck with 11/16" on the left plate and 1" on the right. Got the rear back laced up and the 16" rear wheel looks tiny! still waiting for my wheel builder for the front which will also be a 16" and the hub... a pair of half width bsa 8"ers pressed apart and pressed together with the non brake half put on the parts shelf. No BSA parts were harmed in this exercise, they could be reinstated if I wanted poorer brakes! Hope to have it on two wheels by close of next week, just need to sort out the trail, may end up making new sliders with a leading axle and a brace between them.

Title: Re: 1956/58 alloy rear hub axle diameters
Post by: Rocket Racer on 16.10. 2009 04:57

small spacer in new center sleeve the 2 halves are pressed onto. rather neat and technically a period bsa a10 brake! no late model triumph tls brakes on this baby.

Title: Re: 1956/58 alloy rear hub axle diameters
Post by: muskrat on 16.10. 2009 09:21

Mate I love it. Would look at stronger fork legs to handle the extra forces. Well done.
Cheers