This thread has been interesting reading - my first change of tyres on a new bike and a good mate did the job. Yet, a couple of scratches occurred on the rim....ouch.

He had rubber 'guards' over the metal 'leverage sliders', yet I could see they moved when the tyre was rotated trying to get it on the rim.

He assured me that it was fairly common for the rim to get scratched, despite all due care.........although the posts here indicate it shouldn't happen.

I'm sure he is a perfectionist too.....maybe I had upset him somehow.