I sill have all 320 in mine .. 20 years of occasional use.

Mount and Ground W 26"/1.9"wide (Wide, Snow Cat, Rims )

fortunately there is a stud replacement tool sold , Now ..and replacement studs .

the lack of studs down the center of the tire is what makes them cope with ice free pavement .

they are still skate like when walking the bike on indoor .. floors ..