dave m
Oakley Enthusiast
All interesting info, so it looks like basically they were built to a price and we are lucky to find anything in half decent condition these days!To expound on this a little further - The method of holding the lens in place on Blade, M Frame, and M2 glasses is to mis-match the curve of the frame and lens. Putting them together requires both to flex and the tension, along with the friction from the lens in the frame, keeps everything in place. You're in essence loading it like a spring.
To borrow the definition of Static Fatigue from the science dictionary.org
--"The phenomenon of a material failing at a smaller load than that required to cause short-term failure, after a period of constant loading by the smaller load; the load necessary to produce static fatigue decreases with increasing time under load. In brittle materials, static fatigue is due to the slow growth of sub-critical cracks to a length at which they will propagate catastrophically; in ductile and/or viscoelastic materials it is due to the progress of plastic or viscoelastic deformation ie creep to the point where catastrophic yielding can occur."
The early plastic used in Oakley's frames were thin and brittle.
This sounds odd to me. They were described as being used (read: not new) condition, but never actually used (red: worn)?
I'm happy with what the seller and I worked out he was a decent chap sounds like it might of been damaged/squashed in the post but he's going to talk to them about that. Not sure I'd think about wearing them having read that info thugh (and the fact that 12 year old me it seems had a different shaped head!)
Thanks again for all the replies!