A10 thin flange barrel / cylinder wanted

[Andyhosie]

A10 THICK flange barrel / cylinder wanted
prefer standard  bore (i know that may be a big ask) but will consider all
please contact me andyhosie@hotmail.com

Cheers Andy (melbourne Australia)

Is thick flange barrel that I need....I was led to think was a thin one ...but NOT

[Andyhosie]

Opps I may be wrong, I was always led to believe that the 54RR used a thin flange barrel....but I have just stumbled on to some litrature that says;
"In 1954 the fin area was increased for the A7 Star Twin, and A10 models. In the same year the A7 SS had an alloy head with a seperate inlet manifold until 1955 when it became integral. (here's the bit about the RR)..Also in 1954 the Road Rocket gained an alloy head and the famous thick flanged cylinder, which is 1/2" thick insted of 3/8", this was fitted to all the 650 models from 1958".

So it does seem that the thick flange cylinder was introduced on the 54 RR then shelved for a few years?
I will do some more research on this, and if any one else can please shed some light...
As I have stated previously..no one knows everything........... (although some claim to)
Cheers
Andy

[terryk]

I have both barrells Andy Im in QLD

gflash11@hotmail.com

[trevinoz]

Andy,
            If you can believe the parts book the RR had a small journal crank and thin flange barrel in '54/5.
The heavy sold crank was used in '56/7 and thick flange barrel.
Trev.

[Andyhosie]

Yes Trev that is right, now who to believe? From all my previous experience i thought that 54 and 55 used the thin flange. Maybe the other info that I have found is unreliable and incorrect.
What about this; Can a small journal crank be used with a thick flanged barrel? I would think not but am open to any thoughts.
cheers

[trevinoz]

Andy,
            You can use either crank with either barrel.
I am going to use a small journal crank and thin flange barrel on my '54 Rocket, if I ever get to it.
Trev.

[Rocket Racer]

My '55 road rocket was thick flange but small journal. The other models stayed thin flange pre '58 but not the road rocket.
I have some thin flange barrels if you want one, is your bike a road rocket or a gold flash?
I'm travelling to Melbourne mid Jan

While I hate to do it as he's often wrong but to quote Roy Bacon in the BSA buyers guide  "The 646cc engine had been given a thicker block base flange and revised method of bolting the flywheel to the crankshaft for the road rocket in 1954. These features went onto the A10 engines for 1958..." p80