I have designed the strap to be just long enough to allow the bag to hang so that it tops your bike seat. It's 37.5" long. The strap also is wider where it attaches to the sides of the bag, then tapers toward the center so that it's comfortable and stable on your shoulder, super strong, and lends great balance to the bag.
Other than that, this is the Urban Chic bag, sewn in canvas, with faux leather lid and outer pocket. It's got that huge 4" wide gusset so the bag sits flat and upright. Across the front, it measures 14" at the bottom, tapering to 12" at the top, and it's 10.5" tall. On the interior, there's a sectional (2 portions) pocket stretching across one whole side, at 7" tall. On the other, a split accessories pocket to isolate your small things. Each pocket is big enough to fit a Smartphone. There's also a 9" tall pocket made in the faux leather spanning the back side .
This one has a light cocoa snakeskin faux (or, vegan) leather lid, making the front waterproof. The lid is lined with Kona cotton, and interfaced with felt. The body is a chocolate-colored 10 oz. canvas. The interior is a yummy turquoise canvas, and there's a layer of interfacing beween. The pockets are lined with navy Kona cotton. The strap is the two layers of canvas, with interfacing.
There's a magnetic snap to close the top of the bag.
All the fabric surfaces are supported with fusible interfacing for strength and structure. Like all my bags, this one is built to last. Beautiful and strong. Like you.
*** NOTE: Last picture for size reference.. not this exact bag .. model is 5'2" ***