The Superbe/Sports only came in two sizes:Too Small or Too Tall. It never made any sense, don't worry about it.

My '68 Superbe was 21 9/16" (or some Whitworth/Imperial Gallon nonsense) and was just fine for my 5'9" ( .4675 Hectare ) self.

Persons a few light years taller might prefer the 23 8/32" frame if less than 8 Stone.
Back in my day 1 Stone was plenty good unless Willie Nelson was playing at Armadillo World Headquarters, then it was Superbe.

-Bandera