It is the direction of the seams / molding lines / material thickness and type. A radial tube needs to be stronger / better made in order to deal with side wall flex.

Bias tires flex the tread and have stiff sidewalls. This results in lots of road friction as the tread scrubs across the road.

Radial tires have a stiff tread and flex the sidewalls. This results in less road friction as the flex is occurring in free space.

Have a look at this for tube info.

https://www.tireinnertube.com/faq-s

Michelin tires for a long period of time had a reputation of rim leakers around here. Have not heard this complaint for some years though at the same time. The wives car has a very expensive set of Michelin studded snow tires still on with no issues. They even are wearing slowly.

I use a shop that always cleans the bead area of the rims and applies a sealer. I have no idea of how common the application of a sealer is. Yet I never remember it being always applied at any other tire shop.

Some put some form of lubricant on the bead portion of the tire to perhaps aid it sliding over the edge of the rim was not uncommon though. The chains where you buy tires with installation included. Never seem to do much of anything in many cases. Most the time this is okay it seems. At least in my experience.

The odd part of this is the place I use and preffer is not a tire shop. You cannot buy tires there. I usually give them the set coming off the car as they are still serviceable. At least on my wives cars. I want to keep her with deep tread to reduce the chances of hydroplaning. Todays tires are lower profile with wider tread and the cars are lighter in weight.

Thinking back to the time the cars she drove were almost junk in some cases. In those days she was not out on the highway very often either. We can easily afford to keep her car with almost new tires . She gets 43 cents a kilometer or 60 cents a mile car allowance for every mile she books.

I am recovering from cancer surgery once again. It will never kill me but is known and expected to reoccur every so often. This was the third time in 18 years. So I slept in a little. Actually I am doing well at recovery. Just have to take it very easy for a few weeks. Till the healing is done.

As I came downstairs the wife was gone. I remembered that she has to be in a city 70 miles away early today. These excusions to a few places are now almost a daily thing for her.. Weather dependant.