Bags and covers Handlebars bags Powerbar Energy Bag Powerbar. Designed to be positioned directly behind the stem, the PowerBar Bike Energy Bag is flatsided to accommodate most packaging and includes an internal zipped pocket. Four Velcro straps ensure there bag is fastened firmly, even at high speeds and on varying terrains. Easily accessible, this bag is big enough to hold around five small items. So it could be a couple of Energize bars and a few Gels, or any other combination of goods that will keep you going when you start to flag. PowerBar Bike Energy Bag Features : Stem/Top Tube Fastening. Holds Energy bars and Gels. Powerbar logo.