During the 1950's, as the years progressed and the A10 engines were developing more and more power, barrels were regularly breaking away from their flanges so BSA produced the "Thick Flange Barrel" in the hope that it would cure the problem. I think that it probably did when they were sort of new but now, as these barrels are at least 45 years old, they could be suffering from metal fatigue and obviously won't be as strong as they were.
My A10GF is running on a thick flange barrel but I decided to fit low compression pistons in the hope that I would achieve more reliability. I don't think it makes that much difference to the general running of the bike. It cruises comfortably at 65mph even 2-up and loaded up with camping gear. And it hasn't given me any trouble for the 6 years it has been on the road, attending four continental rallies, several British National Rallies and club camps.
However, I will post an interesting story shortly about preparing it for the Danish BSAOC International Rally in 2005. Worth waiting for?? We'll see and let you be the judge!!
Beezageezauk.
