If I was having that much trouble fitting a tyre I definitely wouldn't risk taking it out cycling for fear of getting a puncture and being unable to get the tyre off and therefore stranded. I've been able to get almost all tyres I've tried off and onto the wheel without tyre levers (Including a few road tyres), all by making use of the circumference of the rim being less in the centre than at the edges of the rim, so moving the tyre bead to the centre creates enough slack that the tyre can be removed without levers. I may also have pretty strong hands, but very little strength is needed for most tyre/rim conbinations.

Certain tyre and rim combinations are fundamentally incompatible though, one example I've seen first hand was a Hutchinson Octopus DH tyre on a Mavic XM 819 rim. The tyre beads were so thick that only one would fit in the centre groove of the rim.

gorehound wrote (see)

Pity we don't have heated floors in england.

Mike Spence wrote (see)

gorehound wrote (see)

Pity we don't have heated floors in england.

You don't? 

Mike Spence wrote (see)

My bathroom has underfloor heating.  It's not a new concept.