Originally Posted by
tricky
Aluminum frames? 10 years. Carbon? Probably just a couple years, one owner, a good brand and no obvious trauma.
Steal? No time limit, just comfort and availability and ease of installing replacement parts.
I'm not sure about the stolen bikes....
As for the others, I currently regularly ride a 100% carbon bike (carbon lugs) from about 20 years ago, and have no plans to retire it in the near future. Early bonded frames had issues with bond failures, but there is no reason the carbon fiber shouldn't have as good or better long-term fatigue resistance than other frame materials.
There are plenty of aluminum bikes form the 90's and early 2000's that are excellent quality.
I'm not sure about 80's aluminum, or even older aluminum frames. There may well have been a favorable technology shift in the early 90's.
Likewise, I have no problems using old aluminum wheels, hubs, or derailleurs. Although, again, there may be some technology changes making modern wheels better including rim hooks for high pressure tire applications.