Wolf Tooth Components | Upper Headset Trek Knock Block | Green | Is41/28.6, 8Mm Stack

Wolf Tooth Upper Headset Trek Knock Block The Wolf Tooth Upper Headset Trek Knock Block is machined in the USA out of aircraft grade aluminum with superior sealing for protection against the elements. These upper headsets are for Trek frames with molded-in internal bearing cups. Knock Block consists of a special stem and stop chip on the frame. The stop chip limits the turning range of the custom keyed headset cover and the top of the headset cover has notches that lock into corresponding notches on the headset spacers which also correspond with notches in the stem for the strongest connection to the steer tube. Features Designed to work only with Trek Knock Block system The top cap on these headsets have unique raised features that key to Knock Block-compatible stems (made by Bontrager)If spacers are needed, you will need to use special Knock Block-compatible spacers with notch features | Wolf Tooth Components | Upper Headset Trek Knock Block | Green | Is41/28. 6, 8Mm Stack