Every day I commute to the Porter rucksack on bicycle 30 km the university. In university I then use it as a backpack. The typical load consists of 1 laptop, scripts, writing materials and a bottle of water. After just 10 weeks time at the clip-on the luggage carrier is a rivet on the back (plastic web which is mounted on the rack) tripped. On closer inspection, I saw then that already 3 had dissolved by 6 rivets. Because I was afraid that leach out the last three holding studs, thus crashing the backpack from the wheel to the ground, thus, for example, my laptop is damaged, I have the backpack as a complaint (with costs) sent to Vaude. Now I'm waiting for repair, with the hope that this is free.
Otherwise, the backpack is the ideal model for my application!