It's easy to find specialist packs, and it's easy to find generalist packs, but what's harder is to find a pack that does the few specific things you need it to do well. If those things are day hiking, biking and commuting, you need to check out Boreas.
Maybe it's their artsy San Francisco location, combined with easy access to places like Yosemite, that encourages creativity, but whatever "it" is, their sleek, stylish and functional packs are proof that "it" works. The Lagunitas is a 25L top loader, barely over 2lb, with an off-the-back suspension that won't suffocate your back as you crank out the RPMs. The suspension is highly adjustable, so you can easily cinch it up on the fly for additional stability. There is a thin piece of webbing for an emergency hip belt, and load lifter straps to snug it all up.
The waterproof top lid is big enough for wallet, phone and such that you really need to keep dry. The main body is silicone impregnated and pretty water resistant, and you really can cram a lot of stuff in there. There's a laptop sleeve with another slimmer hydration sleeve piggybacked on it, against the back-facing side of the pack, away from strikes and bumps. The two small side pockets are our only complaint (aside from the price, which is a bit steep for what this pack does), as they're not big enough to stow a hydration bottle or really much of anything. On the plus side, they're zipped for secure storage of smaller items.
Hidden away towards the bottom of the outside of the pack is a daisy chain that allows the Lagunitas to be rigged to haul the odd piece of gear too big to go inside. Overall the design works beautifully on a bike where you've got bottle cages for your fluids. If you don't mind using a hydration bladder instead of bottles on a hike or longer cycling adventure, you'll be pleased as punch as well. The Lagunitas does a few things very well, and does so in style, for a price. But hey look, it's on sale!