Originally Posted by
bikemig
Not surprising that it was something better quality. A lot of bikes were built that way with 531 main triangle and something cheaper and heavier but still good for the fork and stays.
Hi tensile is surprisingly easy to bend. I picked up a Peugeot UE 8. I popped in a 126 mm rear alloy wheel and the stays opened like butter. I was surprised by how little resistance there was.
The modulus of elasticity for just about all steels is the same. If you were to build a frame from cheap steel pipe and one out of Reynolds 953, as long as it had the same wall thickness, they would ride the same. That is, as long as you didn't crank down on the steel pipe frame and permanently bend it. An easy analogy would be to make a spring out of both materials with the same shape and size. They would both bend the same under a small load, then bend back (elastic deformation). At a higher load/bend distance the cheap steel would bend permanently, while the 953 spring would continue to spring back.
So, bending that UE 8 stay easily might have to do with the diameter of the tube near the bottom bracket and large indentations for tires and chainrings. Or maybe you're saying it was easy to bend and stay bent?