Why do you need a different bike for endurance? isn't a long race like the World Champ or Paris Brest Paris a race and endurance test? at which point would you switch bikes?
A good comfortabel race bike should be comfortable on a century as well.
lets see though if I was still racing... I gues the '90 Proto (the red one with brifters) or the '00 MegaProTiXL would do. But for endurance like a century I think I may take the '90 Proto (the good Celeste one) or maybe the '87/'11 Cornelo, the '89 Equinox would be a good choice, then again maybe the '88 Trofeo...... Tought choice. OH if it is raining I'll have to use the '86 Volpe with full fenders.
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“One morning you wake up, the girl is gone, the bikes are gone, all that's left behind is a pair of old tires and a tube of tubular glue, all squeezed out"
Sugar "Kane" Kowalczyk