We load the Black Diamond Street Creek 30L RT Backpack for days that open at the gym and close at the office. A dedicated 15-inch sleeve carries the laptop on the outside, and an internal security pocket holds a wallet and keys through the climbing gym session. What Our Gearhead(R) Experts Are Saying:"I roll the top down before the first pedal stroke, and rain runs off the fold instead of into the main opening. On a damp commute, that closure is the weather protection I rely on."