Rent a Callbike for €0,08 per minute (maximum €15 per 24hrs) and pay by credit card. The slightly clunky bikes can be found parked at terminals throughout Berlin, and need to be returned to one as well; find all locations online or with the free app. Register your credit card and choose a pin code via the screen at the terminals, online or via the app, all in German only, or by phone in English.

To rent a Call a Bike, insert your credit card into the terminal, select the bike number you want, and it unlocks automatically; you'll need to activate the lock by opening the metal cover by the rear wheel and tapping the screen; then extract the metal pin, place it into its holder and off you go. To lock it temporarily: insert the metal pole through the back wheel, press the lock button, confirm you'll be back by tapping the screen, and it will display the pin code you need to unlock it later; note that you'll still pay when parked. To unlock, tap the screen and then enter your code. To return the bike, simply park it at any of the Call a Bike terminals and lock it; it will automatically check you out, and confirms this on the screen.

For the smoothest bike ride, select the latest model, those without the shock absorber below the saddle.