So your saying that you’ll just use more people to push the sidewall down? Doesn’t that cost the shop more money as the division of labour is concentrated on the single task where as they could be working on something else?
You only served to prove my point that it takes more time for 1 person to mount tires on larger diameter rims.
When I mount tires on my 16" rims, I’m also 10x more careful not to ruin the polished aluminum lip thus taking a bit of extra time to setup the rubber guard (cut hose) and position it accordingly. If I was being paid by the hour, it would cost the owner more money…
Thirdly, larger diameter rims require newer machines. Newer Machines cost money… duh. If there’s a machine dedicated to 17"+ rims then I don’t see why it wouldn’t cost more to mount them.
Just like anyting in a shop, everything is an investment with expected returns over a period of years.