Originally Posted by 63rickert

In original post there is an assertion that stiffness does not matter for the racks mounted on a bike. Because if they weren’t stiff enough they would break. Umm, racks do break, they break all the time. Current custom builders are using bigger diameter and stiffer tubes than ever previously in the history of bikes. In hopes they won’t break. This would include custom builders who are still using 1” and 1-1/8” frame tubes.

Second post brings up stiff versus sagging car doors. ???? Car doors sag because of wear and free play in the hinges. A stiff car door would be one that required some force to make the hinge move.

Discussion of bicycle stiffness is normally continuous non sequiturs.

The Eddy Merckx hour record, still unbeaten after 49 years, was done on a Colnago built with Reynolds 22/28 butted tubes. In old style skinny diameter. Converting British wire gauge to metric gives wall thickness of 0.711/0.376mm. Of course Reynolds never produced anything accurate to 0.001mm, that is just how the nominal converts. But the skinny belly of the tube was less than 0.4mm. Every Category 6 rider knows that such a frame is impossibly flexible and noodly. What was good enough for Eddy would be laughed out of current market. When you can put out 750-800 watts continuously for an hour get back to me.