I thought I'd post this.
When I first started in this side of the business I had a few things to learn . When changing tires on theses rims there is a little trick to get the tire to seat on the bead . A long time ago I use to spend a fair amount of time trying to get these on . We tried sealing the air gap with greasy tubes etc . Getting a couple of guys to hold it up enough for the air to grab and after many tries and frustration + loosing 5 lbs each it would go on the rim . Not sure how I found this out but assume it was on one of the tech sites .
After getting the tire on the rim your looking at this impossible gap to get the air to push the tire onto the bead . Valve stem up .
The trick to getting them on is flip the rim and tire to the other
side on the tire changer. and fill the tire up with the valve stem on the under side . These rims have a huge shoulder and the tire will grip that side when it's flipped . Then you just push the tire down and put the air in . Easy .
This is what the gap looks like now on the underside ...valve stem down .
These two took less time to mount than drinking a cup of coffee . I get a chuckle every time I put these on . Old memories . Lol
PS: I just have a 99$ tire changer . pretty much will do anything here .