Interesting the added wear from being... not sure what (puzzling). BTW in this design they are meant to be able to pass through. First time that happened to me I was like, WT... The modern bushings are steel with copper flash and Teflon-like stuff. Very durable. They aren't meant to run tight on the stanchions and there is some clearance for a little felt play. In the very old days it was chrome plated steel on steel or cast aluminum and quite prone to wear. "They don't make them like they are used to" and thank goodness!