The SuperChampion Arc-en-Ciel, nominally 330 grams, was also used extensively on the PX-10. I think Mavic supplanted them sometime in the 70s.
Regards,
Jerry Moos
brian blum wrote:
> The GP-4 are the same weight and cross section as the Mavic Montherly
> (was it also labled Record du Monde?) used on the PX-10. About 400 grams
> and probably a different aluminum alloy. That seems to be what I recall
> anyway. BrIANCHIlly in Berkeley