Steel rollers on 1953-era track take a beating from the cold swings this area gets every winter. Steel contracts, the track narrows a hair, and a roller that rolled fine in October starts grinding by January. On a street of houses built in the early '50s, you'll often find one or two rollers already swapped out individually over the years - a quick fix by a previous owner or a prior repairman - which leaves the set mismatched: some steel, some nylon, different diameters, uneven wear across the ten rollers. With median income in Camp Hill running near $111,000, well above the roughly $80,000 median across the wider service area, more owners here go straight to sealed-bearing nylon rollers instead of replacing one steel roller with another cheap one. That's the right call on a door this age - nylon doesn't suffer the same cold-weather contraction steel does, and it doesn't need periodic lubrication to stay quiet.