Apollo’s RFZ DB Z40 dirt bike features a 140cc engine putting out 11hp. A 33-inch seat height and 17-inch front tire make it perfect for teens and adults. The bike’s twin-spar type, heavy-duty frame, and full suspension. A 17-inch front wheel and 14-inch rear give this bike 13″ of ground clearance making this a pretty good trail bike. The Apollo DBZ40 mid-size dirt bike has a 32.5-inch seat height, a manual clutch and 4-speed transmission, and aggressive knobby tires. Great power-to-weight ratio.