Fuel EX Jr is a real mountain bike modeled after Trek's legendary Fuel EX, with a lightweight frame and custom suspension package that's perfect for little rippers. Speed, fearlessness, fun. his bike is every bit as capable as the adult Fuel EX. All the same features that make it good for Mom and Dad, make it good for junior, including ABP, Full Floater, tapered E2 headtube, hydraulic brakes and performance spec. Fuel EX is a ground-up build engineered specifically for kids 4'4¿¿5' tall.