Rename Gran Fondo 100
Spitting Gran Fondo up into 100km and 150km variants is a good idea. But the names are too confusing you say you've done a Gran Fondo well which one? And saying "I've done a Gran Fondo 150" sounds cludgey. My suggestion is keep the Gran Fondo name for 150km but rename the 100km. I've already seen people calling it the Mini Fondo or perhaps Piccolo Fondo to keep the Italian theme.