the 2nd volume on BSA unit twins , following on from Vi Thunderbolt and Lightning, by Peter Crawford, is now available from Wideline Publishing, price £25 plus postage.
Great news! Vol 1 is one of my favourite bike books, exceptionally well written, with loads of first hand information from those involved. Just ordered this new one and very much looking forward to seeing it.
Not giving anything away, but how lovely, very well written, impossible to not bust out laughing at the first hand experiences and stories of racing the twins.