Front Hub Bearing: 139QMB Scooters

Smooth Rolling: High-Precision Front Hub Bearing

Restore the handling and safety of your scooter with this High-Precision Front Hub Bearing. Specifically designed for the 10mm axle systems found on Chicago Scooter Company models and 139QMB (GY50) Chinese scooters, this bearing ensures low-friction rotation and a stable front-end feel. Whether you are experiencing wheel wobble, "grinding" noises, or performing a routine front-wheel service, this OEM-spec bearing is the standard for reliable urban commuting.

Technical Performance Features

• OEM-Spec Geometry: Features exact 30mm OD / 10mm ID dimensions for a press-fit installation that matches the factory tolerances of your front hub.
• Dual-Shielded Design: Equipped with protective shields to keep road grime and moisture out of the internal raceways, significantly extending the life of the bearing.
• High-Speed Rated: Engineered to handle the RPMs and lateral loads of 10-inch and 12-inch scooter wheels at full city speeds.
• Low-Friction Performance: Reduces rolling resistance to improve fuel efficiency and provide a smoother, more predictable steering response.

Comprehensive Fitment Guide

This bearing is a direct replacement for the front wheel assembly of the following 50cc 4-stroke scooters:

Technical Specifications

• Outer Diameter: 30 mm
• Inner Diameter: 10 mm
• Thickness: 9 mm
• Bearing Type: 6000 Series (Verify size on old bearing)

Mechanic's Note: Wheel bearings should always be replaced in pairs to ensure even wear and balanced handling. When installing, never strike the inner race of the bearing; always use a Bearing Driver Tool or a socket that matches the diameter of the outer race to press the bearing into the hub. For the best results, clean the hub bore thoroughly and apply a light film of High-Temp Grease before installation.

SKU: 0600-4003
MPN: 3500136

Front Hub bearing for CSC Go or 139QMB Chinese Scooter

Outer Diameter: 30 mm
Inner Diameter: 10 mm
Thickness: 9 mm