I have a Camelbak Kudu 12 (http://shop.camelbak.com/kudu-12/d/1344) backpack. I've tried riding with it a few times but it's just not working. Whenever I ride down a trail, the backpack hits the back of my helmet. Because my helmet has a click to tighten on the back, whenever my backpack hits the helmet it undoes it, making it bob around in front of my eyes. I cannot ride when I'm using this backpack, I've tried tightening the straps fully and everything. Any tips? Cheers
Edit: this is the tension control on the helmet, as you can see you push it and it loosens.
Update: I've cable tied the tension control together, so that when the backpack hits it, nothing happens. works great!