Trek Knock Block 72-Degree Headset Non-Block Frame Chip, Headset Upper Assembly (Bearing Cover, Frame Chip & Fastener) Ships within Australia In stock. Available via Click and Collect or Buy Online Share Loading Facebook Like button... Trek Knock Block 72-Degree Headset Non-Block Frame Chip, Headset Upper Assembly (Bearing Cover, Frame Chip & Fastener) Ships within Australia In stock. Available via Click and Collect or Buy Online Share Loading Facebook Like button...