Hello Mates:
The reason that I asked this question is that a "diesel" expert" informed that the reason was due to the following fact. Post WWII due to a shortage of steel, the diesel cylinders were made from frames of bicycles. This tubing would yield a cylinder that was 15mm. This tale while romantic, seemed to be a bit over the top. If true, why had I not heard about it through out the years?
Perhaps this is a well guarded esoteric secret know to only a few. In any case, has anybody learned about this idea?
Be well,
Franchi