Originally Posted by
droobieinop
Those little clamps are good, however, some bikes have tubing that is larger than the clamps that come with your average rack. Another option for the toop of your rack is a seat clamp that has braze ons manufactured into it.
you can find very similar clamps at a hardware store in a range of sizes, they are used for securing plumbing. the only downside is they tend to be galavanized rather than stainless/chrome, so they get pretty nasty looking after a few years outside.... like these...
I went and used M3 metric allen stuff with them when I used those to put a rack on a that had no bolt holes. I only used them for the bottom end of the rack, the top side, I did something with the brake bridge between the seat stays.