The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => A7 & A10 Engine => Topic started by: steverat on 24.07. 2011 18:19

Title: Thick flange barrels for A7
Post by: steverat on 24.07. 2011 18:19

Good evening all.
I am considering the purchase of a mid-fifties A7 which has thin flange barrels.
I have owned several A10s and always understood the thick flange to be a safer option.
Was the thick flange ever fitted to A7?

Regards
Steve

Title: Re: Thick flange barrels for A7
Post by: MG on 24.07. 2011 18:26

Hi Steve!
The A7 never had thick flange barrels fitted. There is much more material left in the spigots, around the flange area, because of the smaller bore diameter, hence it wasn't necessary.

Title: Re: Thick flange barrels for A7
Post by: steverat on 24.07. 2011 19:42

Thanks MG, good to know!
Now I know why my search for 'thick flange A7' on Ebay was a bit fruitless......

Title: Re: Thick flange barrels for A7
Post by: MG on 24.07. 2011 20:20

If you ever find one, then you should buy it right away, because most likely it came off a Daytona Shooting Star competition bike.  *ex* *smile*
They seem to have had special castings for those, 3/4 years before the A10 thick flange barrels were made. Note the very substantial flange (must be more than 1/2"), and 6 smaller fins, instead of 7 on the normal A7. Maybe they modified a mould for plunger barrels.  ???? ???? ????

Useless info of the day  ;)
 
Cheers, Markus

Title: Re: Thick flange barrels for A7
Post by: muskrat on 25.07. 2011 01:04

Your a wealth of knowledge MG. I wish I had those barrels when racing the SS, the thin flange gave way 3 times for me.
Cheers

Title: Re: Thick flange barrels for A7
Post by: A10Boy on 28.07. 2011 09:27

Musky, you should have tried through bolting.....................  *smile*

Title: Re: Thick flange barrels for A7
Post by: muskrat on 28.07. 2011 10:16

Still do, even thick flange.
Cheers