It was during one of Tullio's races as an amateur that he confronted a problem which often faced cyclists of those days -- removing a wheel. On November 11th, 1927, with snow covering the roads of the Italian Dolomite mountains (that's him in the photo, on that very day!), Tullio was riding over the Croce D'Aune Pass in the Gran Premio della Vittoria race and needed to remove his rear wheel to change gears (more on that below). Because the large wingnuts that held his wheel on had frozen and his hands were too cold to budge them, he was unable to remove his wheel to change gears, and lost his chance at victory that day.
As he struggled to free his wheel, he muttered five words to himself that changed the history of cycling:
"Bisogno cambiá qualcossa de drio!"
Those words ("Something must change in the rear!") and that simple event -- a wheel that couldn't be removed -- started Tullio thinking. He went back to his workshop, and emerged with the invention of the quick-release lever (in 1930) and, soon after, an early bicycle derailleur (1933).