Originally Posted by
pdlamb
Not knowing the history of either frame, I'd go with the newer one. It has had less time to rust or fatigue. While there are no guarantees either way, I'd think a 7 year old bike would be less likely to break than a 24 year old bike.
As I wrote previously both frames are in same good conditions, good paint, no rust, but I think you have a point: you can't see fatigue. I'll go with 520: +20mm chainstays and younger. Thank all for your kind and fruitful advisement.