ROCKBROS 12L Bike Trunk Bag, Expandable Waterproof Rear Rack Bag, Bicycle Pannier Rack Storage for Commuting Touring
1. Product Description Transform your bike into a cargo-ready commuter or touring machine with the ROCKBROS 12L Expandable Rear Rack Trunk Bag. Designed for versatility, it starts at 9L for streamlined day rides and expands up to 12L when you need extra storage for commuting, grocery runs, or overnight adventures. The rugged polyester exterior is water-resistant, while the included rain cover provides full protection during sudden downpours. Inside, a removable divider helps organize tools, clothing, or electronics, and thick foam padding keeps your gear safe from bumps. Fold-out side pockets add quick-access storage, while the adjustable drawstring bottle holder ensures hydration is always within reach. Safety is built in, with reflective straps and a taillight-compatible rear loop to boost visibility in low-light conditions. Four reinforced straps secure the bag firmly to most rear racks, including fat bike and e-bike setups. When off the bike, the detachable shoulder strap makes it easy to carry as a standalone travel bag. 2. Product Specifications Brand: ROCKBROS Material: Polyester Capacity: 9–12L (Expandable) Weight: Approx. 566 g Mount: 4-Strap Rear Rack Mount Features: Rain Cover, Reflective Straps, Removable Divider, Carry Strap















