I’m sure the C456 should be the same as the metal one of the same year.
Ben, this is the spec for the Ti but the geo is the same for the Pig- there’ll probably be some details like headtube etc that vary though
Frame Size Top Tube (effective) Head Angle Seat Angle Chainstay BB Drop BB Height with 2.5?s
16in 23in 67.5deg 73deg 16.73in 0.8in 12.4in
18in 23.5in 67.5deg 73.5deg 16.73in 0.8in 12.4in
20in 24in 67.5eg 74deg 16.73in 0.8in 12.4in
Seat tube diameter :: 34.9mm outside (constant), 31.6mm inside (seatpost size).
Headtube :: 1.125in standard external.
Geometry is set for contemporary 140mm travel forks. It will happily take 130?s or 150?s.