Rollers wear out everywhere, but the pattern here has a specific shape. The service area sits in a moderate heat climate band, which means the garage door track goes through real daily temperature swings - cool mornings, hot slab-radiating afternoons - most months of the year. That expansion and contraction works on the track bolts and roller stems slowly, and it's worse on doors that get full sun exposure for part of the day. Add to that the age spread in this housing stock. Homes built in the 1980s and 90s, which make up a large share of the 31 named communities in this area, often still have their original galvanized steel rollers with steel bearings - no nylon, no sealed lubrication. Those rollers were fine for their era, but thirty-plus years of use plus heat cycling is exactly the combination that grinds out a bearing. Newer homes built closer to 2014 are less likely to have this exact problem yet, but the ones built in the 1990s median range are right in the window where original rollers start failing in clusters, not one at a time.