I COULD NOT mount brand new Conti "Handmade In Germany" tires on my old Fulcrum Racing 5s from 2006 without levers. I used to mount them on another bike with Velocity rims first, run them for a week or two, THEN move the stretched tires to the Fulcrums.
This year I discovered the old Fulcrums developed cracks at most of the spokeholes in the rear wheel. So I got a new set Racing 5s. New Contis go right onto those without an issue, and can even be taken off without levers.
I wish somebody'd told me about the Trek Matrix rims, though. I just bought an old RX100/Matrix wheelset for my 1994 Cannondale, and I had a hell of a time getting tires on them, even with levers.
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"Don't take life so serious-it ain't nohow permanent."
"Everybody's gotta be somewhere." - Eccles