thick flanged barrels

[groily]

Well I never heard of the thicker ones doing that Trev, have to say! Talk about live and learn. I'll just keep my fingers crossed that a pretty soft bog standard motor like mine will not do these sorts of things. To have lost one  - unfortunate - but 2 . . . careless - as whats'ername said in another context altogether! Interested to hear about how you are getting round the hassles though as you re-sleeve etc.

[Brian]

Like I said I have never had a set let go but I am curious.

If they dont actually break at the flange but above then I wonder why BSA went to the thicker flange to try and address this problem. Maybe the thinner flange allowed some degree of flex or movement in the base of the barrels.

I have never road raced a A10 but in my youth had a A10 scrambles outfit. I dont know what compression ratio it was but is was as high as we could get it without the pistons hitting the head. We flogged that thing mercilessly but it never broke. I dont recall what year it was but it was a very early swingarm model so would have had thin flange barrels.

That thing taught me that three wheels is a bad combination, I have stuck to two or four ever since !

Brian.

[groily]

'Three-wheels a bad combination' - nice pun Brian.
Sidecar mates tell me I'm a girl's blouse, but I have never got in with them either. I'm completely incompetent with them, and inspected ditches and verges various on the few occasions I tried to learn the art.
To keep vaguely on the BSA topic though, one rat-bike I had with a chair was a real weird one - Plunger A10 with, yes really, a 998cc Morris Minor engine transversely mounted, driving a BSA box through a triplex chain. Electric start, with     electric fuel pump, 7 gallon tank and big car battery plus remote radiator ( all in the chair). Built by a resourceful plumber in Portsmouth in the early 70s/late 60s, who was probably only too pleased to find some fool to give him 30 quid for it. Only went to the pub on it a couple of times. No-one was quite sure about the - er - number plate details but soon got rid of with a lot of other stuff I wished I had kept when my old dad demanded his garage back. And the chair - or chassis - was a Swallow. Ouch.

[A10Boy]

I think the CA10s had the 3/8th flange and small journal cranks, then in 58, when the DA10 engine was introduced BSA used think flange and large journal crank across the range with different camshafts etc.