Last month, my LBS had their big, annual blowout sale, and I scored some Trek Interchange panniers for my commuter (Surly Cross Check, if anyone's curious). I'm a pretty aggressive rider on my commute - I'm often up off the saddle sprinting to keep up with traffic, merge, whatever. When I do this with the panniers, though, I have problems with them swinging around, falling off, etc. Today, a bungee cord that was hanging out of the mesh pocket on the back got caught in my spokes, and pulled the pannier into the wheel!

They use a plastic knob that's supposed to hold them to the side of the rack, but it doesn't seem to work well, especially when they're mostly empty, with a single heavy item (like a lock) flopping around in the bottom.

My question: is this an inherent limitation of all panniers, or did I just get crappy ones? If it's an inherent limitation, I'm going back to a messenger bag or backpack, because I don't have a relaxed, Copenhagen-style commute. Riding less aggressively isn't really an option.

If it's just that I have crappy ones, what are some better (more secure) ones I could use? I'd lean strongly toward Vaude, because I can get a deal (their distributor sponsors my club), but I'd like to hear if anyone has some real input.