Trek Madone 9-Series Upper Headset Bearing (48.9 mm x 37 mm x 6.5 mm) Ships within Australia In stock. Available via Click and Collect or Buy Online Share Loading Facebook Like button... Trek Madone 9-Series Upper Headset Bearing (48.9 mm x 37 mm x 6.5 mm) Ships within Australia In stock. Available via Click and Collect or Buy Online Share Loading Facebook Like button...