This is one of my first attempts at a courier-style bag.
The outer flap is securely held on velcro, with additional external straps for extra security, or for expansion. Inside is a zipped divider, with pen and phone pockets sewn in.
The large buckles are recycled from parachutes. The additional chest strap may be attached to them for cycling, with the bag on either side of the body, or removed for pedestrian carrying. The tensioning buckle for this strap is designed to slide loose when released. This automatically loosens the strap, ready to put it on next time and tighten it with a single pull.
The green fabric is interesting; it's two layers of a Cordura-like material with a rubber layer between them. Flexible, waterproof and no proofing to wear off. After two years of daily service, one of the prototypes is still waterproof enough to carry water.
A later courier bag switched to Kevlar fabric, for extra strength and wear resistance. Tough enough to survive a Volvo taxi, this is the only bag for the Urban Courier.
Kevlar isn't waterproof, so the bag is lined with a proofed Cordura inner.
An outer pocket under the flap keeps keys and loose change handy, without rummaging in the main bag.
Subtle changes to the chest strap location keep the bag under even better control when riding off-road.
A zipped inner divider keeps phone, PalmPilot and pens under control and still leaves room for a Mars bar.
More Cycling bags