Originally Posted by
KraneXL
If you're going to be regular commuting its better to find something you can put on the bike rather than your back. That is anything greater than a slim hydration pack I'll certainly never do it again. Its just too darn uncomfortable.
Man, you're opening the backpack vs rack debate.
I would go with backpack every time. 20L is perfect for multimodal commuting / shopping in an urban area. If I cycle to the station, then hop on a train/bus/hovercraft, I'd go with a small backpack as would most people over here.