If you want to avoid a tight fit, do not try the combination I have on my Bianchi -- Campagnolo Omega rims with Continental tires.
Aside: When buying mountain bike tires, you will need three tire levers to install or remove "tubeless ready" tires. In the past, I have not even bothered to carry tire levers with my mountain bike, but this has now changed.
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"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069