Seems like a nice bag. As iwegian said, if you weren't going to use it for hiking, I'd also suggest a messenger. bag. They're great for on-the-bike use, of course. If you want a backpack that's great on the bike, I've read really good reviews about Ergon:

http://www.bikecommuters.com/2008/02...ckpack-review/

Then there are the really nice messenger backpacks:

http://www.chromebags.com/products/bags/packs/

But a rack and panniers are far superior to carrying the load on your back.