Coasters are over 100 years old. The oldest operating coaster in the world is Leap the Dips at Lakemont Park (b. 1902) in Altoona, PA. Leap the Dips operated from 1902 to 1985. Then it sat in decay until 1999 when it was restored.
Unfortunately, many coasters don’t age very well and for one reason or another are never rehabed. Their rides become bumpy and rough to the point where ridership becomes low and parks have to remove them. Other coasters defy their years and still operate as great as they always have. It takes great construction in the first place, a park that cares, and sometimes re-tracking, but some ancient coasters out there run better than coasters a quarter of their age. The Comet at Hershey Park (b. 1946) and the Jack Rabbit at Kennywood (b. 1921) are two great examples. Even Raging Wolf Bobs at Geauga Lake (b. 1988) is old enough to turn into a rotten coaster with a rough ride. It doesn’t take long for things to go south, see the Predator at Darien Lake (b. 1992). Thanks to a healthy re-tracking the Comet, Raging Wolf Bobs, and others have been revitalized and will continue to thrill without giving back adjustments for many years to come.
However, a failed re-tracking isn’t unheard of. My ride on the renovated Cyclone at Six Flags New England was probably my most painful experience on a coaster. I got off feeling more like 62 than 26. Ouch!