Who doesn't like to upgrade their MTB parts?. Now there is a better way for us that ride a Trek bike with Knock Block systems. Designed by riders out of Oregon is the COC Block. CLAMP ON COLLAR. By combining the holding power of the COC Block with the strength of the Knock Block bearing cap, this system will give you the greatest flexibility to customize your handlebar stem, change forks, use standard headset spacers, or use a "kids ride shotgun" adapter.
