Difference Between ZF, BF1, BF3 & Electric Power ZF: With the ZF system, you must move the shift lever to switch between forward and reverse. The reverse gear is actively engaged. BF1: With the Brake Freewheel (BF1), you do not need to shift. You can drive forward and reverse simply by pedaling in the desired direction. At the same time, the integrated back-pedal brake allows you to stop gently and safely. BF3: The Brake Freewheel with 3-speed gear system allows forward and reverse driving without manual switching. The integrated back-pedal brake ensures particularly safe and comfortable braking. The 3 gears provide the right transmission for any terrain. Electric Power: The Electric Power system supports you with an electric motor while pedaling. You can adjust the assistance level to match your needs. A practical start assist makes pulling away easier, even on inclines. Safety and Warning Instructions: The SPORT is equipped with a large swing axle, ball-joint steering, seat bushings, and sturdy mudguards. The DINO CARS SPORT is the entry-level model, prioritizing safety and comfort. The robust tubular steel frame and pneumatic tires ensure a comfortable ride. Multiple seat adjustments make this model a great go-kart for children and adults of all ages, from 5 to 100. Accessories such as front spoilers and lifting devices can be easily added. DINO CARS trailers can be attached to the standard trailer hitch. assembly Instructions Download assembly instructions Technical Explanation of ZF Hub The product shown in the image may differ from the original. Technical data Download technical Data Instructions Electric Power Drive Download Instructions for Electric Power Drive