What is an Underbone Motorcycle

An underbone is a lightweight motorcycle that utilizes a structural tube frame, usually covered with plastic panels, featuring a step-through design where the fuel tank is located under the seat, rather than between the rider’s knees. Known for efficiency and stability, they feature 50cc-150cc engines and semi-automatic or automatic transmissions.

This video explains the main characteristics of an underbone motorcycle:

Key Characteristics and Features:

• Performance: They are designed for fuel efficiency and daily commuting, with engines typically ranging from 50cc up to 150cc, though higher displacements exist.
• Transmission: Most use a semi-automatic (no clutch lever) or full-automatic gearbox, making them popular for beginners.
• Common Applications: Often referred to in Southeast Asia as "motor bebek" or "kap cai," they are highly popular for courier services and daily transportation due to their durability and low cost.
• Distinction from Scooters: While similar to scooters, underbones typically have larger wheels (usually 17-inch) and traditional chain drives, whereas scooters usually have smaller wheels and the engine/transmission attached to the rear swingarm.