Some rim/tire combinations are a "bother" for the initial mounting, but are fine after the tire stretches a bit. You can use one of these:



for the first time mounting the tire.

(It's a Kool Stop Tire Bead Jack.)

Addd in edit: GP Unobtaniums don't stretch, so you'll have to carry this in your jersey pocket or have one in the team car if you ride with them.