A roller set doesn't fail the same way everywhere. Roseville's housing stock, clustered tighter around 1968 than the broader 1950-2002 range across this service area, means a lot of doors are running original or first-replacement steel track with nylon rollers that have outlived their stem bearings. Minnesota's cold winters put steel rollers and their bearings through repeated freeze-thaw cycling - grease stiffens, bearings seize, and the roller stem starts grinding against the track instead of rolling in it. On a house this age, that grinding has usually been going on long enough to groove the track itself, not just wear the roller. We see it as a dragging, scraping sound right before a full jam, usually worse on the first cold mornings of the season. It's not a defect specific to any one brand from that era - it's just what 55 years of Minnesota winters does to steel-on-steel hardware that was never sealed against the cold to begin with.