I recently dug out an old pair of dura ace clincher wheels. Trying to change the tyres on these is like being in a nightmare edition of the Crystal Maze.
These days I find most wheel and clincher/tubular tyre combinations can be done by hand.
If you are using levers to put tyres on, you are risking pinch flats, and worse still rim damage.
One nice tip when installing clinchers is to get a small sponge and coat the inner tube and the inside of the tyre with talcum powder.
When setting the tyre:
Have the valve hole at 12 o’clock, and gradually stretch one side of the tyre downwards and onto the rim from 1 o’clock and 11 o’clock simultaneously.
The last bit at 6 o’clock should be the only bit where you have to force it a little.
The talcum coated tube should slide in snuggly.
Again from 12 o’clock, stretch in the next side of the tyre onto the rim.
Once inserted, check the circumference of both sides of the tyre to ensure the tube isn’t pinched.
Inflate a little. Check for pinching again.
Pump up to desired pressure.