Yes, you can cut down carbon bars and posts. For best results, take your component to a local bike shop for advice and service. To cut the component yourself, wrap it in a soft, removable tape such as masking tape to avoid splintering the carbon. Clamp the part carefully, being sure not to overstress the carbon tubes, and cut at your carefully measured mark with a fine-tooth hacksaw. Use a guide if possible. File the edges with sandpaper or a fine file until smooth. Special note on posts: Please note that certain Profile Design posts have a reinforced clamping zone between the minimum and maximum insertion point. If you cut down such a post, it must still be clamped within the reinforced zone, leaving at least 88mm of the tube inserted into your frame. Special note on bars: Profile Design carbon bars are reinforced at the tips for use with bar-ends. If you cut them down, you will remove the reinforced zone, and the bars will no longer be approved for use with bar-ends. (note that any modifications, such as cutting bars or posts, will void the warranty.)