fastpedaller wrote:Tangled Metal wrote:It's not that just the fact you're the first owner and you know it's full history.
You certainly need to be aware of history or fully strip it and know what to look for.... Many years ago an aquaintance had a nasty accident riding a second-hand bike which he'd just bought. The previous owner had (for whatever reason) butt joined the steerer by brazing (rather than replacing the complete tube) and consequently it failed!
Blimey: sounds like a suicide mission, that....
Having broken quite a few bikes now, I can say with some confidence that 'nothing lasts forever' is a useful axiom, (even if it mightn't be strictly true in some cases). Knowing the way most bikes are built, I'd also say that most frames contain features that are in effect the seeds of their own (eventual) destruction. Sometimes it is design, sometimes materials, sometimes fabrication methods, and very occasionally the bike has seen loads that are abnormal.... but in hindsight every frame or fork that I have broken myself (or have seen others break) has broken for a reason.
If you are buying a used bike with a metal frame, it is easy enough to inspect the frame and fork for cracks. If there are no cracks then you would be incredibly unlucky if it then cracked inside six months of further normal use, so inspections at this kind of interval give some confidence. Obviously the fork needs to be removed in order to check the steerer tube; this is pretty much the only single tube on a bicycle that can break and immediately cause a life-threatening prang; most of the other places where frames break normally still leave you with enough of a bike that you ought usually to be able to stop the (newly floppy) machine before you have an accident.
I would further comment that very few secondhand bicycles have been used so much that (if made properly) they would have the frameset's remaining service life reduced appreciably.
cheers