I doubt there is a tire/rim that is impossible, or even hard, to install with the Pedros tire levers that were mentioned earlier. Park has a similar tool out now. I like some air in the tube while I am getting the tube into the tire, but once its all inside I let all the air out, then start to work the open side of the tire into the rim. Sometimes the last 4" or so are stubborn and sometimes not. If stubborn the Pedros lever WILL get it on and I haven't cut a tube yet in over 3 years of using them.