As can be read in the commuting forums, I had a little incident with my bicycle. My Tubus Cargo rear rack along with my rear rim sustained the brunt of the damage.
I took the steed into one of the local bike shops and asked him if the rack was damaged. He glanced at it and said no, but I'm still in mild doubt. So since I have no pictures, I ask, "Where is damaged typically sustained on racks during normal use, or rather where is the most stress put?"
The Tubus rack is tubular chromoly, and the damage it sustained in my crash happend on the rear-most stay, mostly on the bend between where the tube becomes the stay and the platform. Here is a picture of a Tubus Cargo http://www.peterwhitecycles.com/tubus_racks.asp#Cargo. Most of the damage was scrapes, but a few dents have me concerned. Picture a tin can that has been slightly pinched, or crimped, and you can get the general idea. Though I stress slight - it is not as if the tube is completely caved in or even a quarter way caved in.
The rack is strong, and it took a considerable blow to cause even this damage, probably the force equivalent to a solid wacking with a hammer. I only worry because the rack was expensive, and was new. I guess the only way to really tell if it is structurally sound is to go for a few hundred mile tour with a heavy load, or perhaps just heap my panniers with 75 pounds of firewood.