The messenger bag I posted about yesterday actually was a Timbuk2 bag, WolfsBane. Don't get me wrong, I love the bag, but it frequently shifted into my bike while I was riding. Of course, I was not riding in an upright position, nor did my bag have an extra strap to keep it specifically from shifting. I do love the bag though... I'm about to pick up one of their backpacks because their products have thus far impressed me a great deal