Browsing through adverts for classic big British twins, it’s always been noticeable that prices for BSA’s A65 are significantly lower than for equivalent age and engine size Triumphs and Nortons. When the A65 was first introduced in 1962, it met with a degree of disapproval from existing pre-unit BSA customers – and things didn’t improve initially. This was probably due to the reputation the new model gained in the 1960s for engines blowing up and the frumpy styling of early models, though both aspects steadily improved throughout the 1960s, before the introduction of the radically differently styled oil-in-frame models, in 1971.
The Achilles heel of the A65 – and for that matter its smaller brother the A50 and several contemporary Triumph big twins – was the timing side plain bush and its reputation for wearing, causing a loss of oil pressure and shortly thereafter big end failure, with sometimes catastrophic results involving broken con rods through crankcases. Back in the days when many
