This might be a clue:
Sutherland's Sixth Edition page 10-2, under "Front Hubs", says:
9 - 7/32" balls per side -- Nuovo Record, Super Record, Record*
10 - 3/16" balls per side -- Grand [sic] Sport, Victory, Chorus, Croce D'Aune and others
then, below says:
* Record marked S.U. on center of hub shell uses 9 - 7/32".
Record not marked S.U. on center of hub shell uses 10 - 3/16".
This "Record" may refer to C-Record but it seems logical to infer that SU on other hubs refers (in some way) to the bearing ball size.
Lee Berg Palo Alto
Kerrigan Bennett wrote:
>
> This is probably a ridiculous question, but what does the "S-U" stamped
> into a Campy hub body below the script logo signify?