Originally Posted by eandmwilson
I'm assuming the orientation of the carbon tube was so the loading was axial? If the tube were placed on its side in such a test, I'm sure it wouldn't fair as well. CF is fairly isotropic, and while strong, it is not crush proof.
That being said, I think the majority of owners are a bit paranoid about how fragile their top tubes are. It isn't tin foil, fer cryin' out loud.
NO. You should never clamp the top tube, no matter what the material, it is very easy to deform or crack a top tube while in a stand. These tubes are not designed to be clamped or torqued.
Zinn tells people not to clamp their CF posts, but this is really for those who over-tighten everything, and there are a lot who do this. Bottom support stands like the Park are good for the paranoid, but you have to remove the front wheel every time.
Like everything else, it's common sense, you should just avoid excessive clamping pressure. If you have some ultra expansive, ultra light post, use another type of stand.