Charge Plug Shimano Adventure Disc Brake Gravel Road Bike - Performance Exclusive Charge straight-gauge steel frame is stiff, strong and insanely rugged Promax mechanical disc brakes front and rear offer efficient speed control and dependable stopping power Shimano Sora 18-speed drivetrain offers plenty of gears to choose from Alloy rims are strong and durable Kenda Small Block Eight tires are rugged enough to take you from main street to the mean streets and back