This type of 26-inch folding mountain bike typically uses a standard 17-inch to 18-inch (Medium) frame size. Because of the unique dual-suspension folding geometry, these bikes are generally built as "one-size-fits-most" frames designed to accommodate a wide range of adult heights. The seatpost has an extended quick-release adjustment range (usually allowing the saddle height to adjust between roughly 80 cm and 97 cm) to fit riders anywhere from 5'5" to 6'1" (165 cm to 185 cm). This bike is equipped with a 21-speed drivetrain system.It features a 3-speed front chainring combined with a 7-speed rear freewheel.The gear shifting is controlled by mechanical index thumb shifters (trigger shifters) mounted on the handlebars.It typically utilizes entry-level Shimano or compatible derailleurs to manage the gear transitions.