Vaude Aqua Back Single Backpack - Lightweight Waterproof Hiking Daypack for Men & Women, Perfect for Outdoor Adventures, Travel & Daily Commute (Blue)

I bought this for commuting to and from work during the summer when its hot and I don't want to lug a bag or bagpack on my back. Its been one of the best purchases I've made for my bike. Easily holds a laptop plus lunch and a change of clothes for the gym, and I've never had a issue with it coming unlocked when I ride (and I've got some pretty bumpy roads in AZ).The strap was a big reason I chose this bag, as I don't feel comfortable with leaving it attached (lots of stuff gets stolen around my work). The strap makes it easy to transport and is thin but fine when you're just walking a hundred feet. I've seen some stuff about worrying that the strap will get caught in the wheels but I've found it very easy to fold the strap around the closed clips and seen no issues. Quality wise the bag is tough and all the seams appear to be very well done, its been about 6 months and I've yet to see any issues.