Drinking system for bike backpacks made of FDA-approved, hygienic polyurethane that can be stretched up to eight times its surface area without tearing. The large, continuous opening with a sliding closure allows for easy filling and cleaning. Extra-long, tasteless drinking hose (easily connects to the bladder via plug-and-play) with a 90-degree bite valve. This hose is multilayered and thus completely kink-proof. The internal safety valve of the bladder prevents leaking. Suspension in the backpack using mounting hooks. Suitable for all Ergon bike backpacks.