Gudgeon Pin Size

[Duccout]

This is a question purely out of interest; maybe Nigel or Eldert will have a definitive, or someone may have an opinion: does anyone know why Ducati kept changing small end diameters?

The 250/350 Singles were all 18mm, except the 450 which was 22mm originally, but later became 20mm; the 750 bevel was 22mm, except for the 750SS, which was changed to 20mm, which was also the size of the 860 engine, and then the Pantah reverted back to 18mm, which I believe is still the same size as modern Ducatis. Correct me if any of these sizes are wrong, I am quoting from memory, which is not reliable.

So, is a smaller diameter small end lighter? A larger gudgeon pin can be made thinner, saving weight.......

Colin

[jackbiwa]

A smaller pin is lighter overall and that was probably the primary reason. The 450 piston fits the 860 so having a common gudgeon pin may also have been a factor.

Jack