I have to replace my office chair to post on this site , it broke it's arm so it's for the skip. It's worst fault was not that incredibly, but that the casters rely on the vertical spindles not a thrust bearing making them jam and skate often, on my hardwood floor. Looking for a new chair on the usual website they don't specify whether if they have a thrust bearing or not, can you tell if they have, is there a option to buy new casters if they don't, is the spindle a standard size and shape?