The Viking Bags AXE-30 Motorcycle Backpack works out great on a motorcycle. Check out the video and you can see the full review on SpiritStrike.com
http://www.SpiritStrike.com/gear/2014/6/27/viking-bags-axe-30-large-back-pack
Direct link to manufacturer's product page:
http://www.vikingbags.com/moto-riding-large-black-motorcycle-back-pack.htm
