How well is a modern 25c tub going to sit on classic sprint rims (Fiamme yellow label)?
Perfectly well. Back in the 1960s into 70s the Audax crowd used to worship Clement Campionato del Mundo Seta tyres and the Fiamme yellows were, alongside, Super Champion Arc en Ciel and Mavic Monthlery the rim of choice. Back then 23mm were considered narrow, 25mm were considered the things for training.. and the dell Mundos would be called 28mm today. Wide rims are about clinchers NOT tubulars.
(the move towards more narrow tyres was a result of the improvement in European roads and trend towards aerodynamics, short reach brakes and shorter wheelbases.)
Perfectly well. Back in the 1960s into 70s the Audax crowd used to worship Clement Campionato del Mundo Seta tyres and the Fiamme yellows were, alongside, Super Champion Arc en Ciel and Mavic Monthlery the rim of choice. Back then 23mm were considered narrow, 25mm were considered the things for training.. and the dell Mundos would be called 28mm today. Wide rims are about clinchers NOT tubulars.
(the move towards more narrow tyres was a result of the improvement in European roads and trend towards aerodynamics, short reach brakes and shorter wheelbases.)