The Ritchey 1-bolt alloy seatpost clamp kit is a stock replacement kit for Ritchey 1-bolt seatposts. They come in different slot diameters to accommodate the larger diameter carbon rails found on some contemporary saddle designs. The clamp kit includes the main bolt, washer, one threaded and one unthreaded rail clamp.
There are two sizes to choose from - 8.5mm for larger than standard rails and 9.6mm for Fizik carbon. Beyond the diameter size, you will need to select from carbon or alloy - select carbon if you have a carbon shaft post and alloy if you have an alloy shaft post. These clamps only work with Richey 1-Bolt seatposts and cannot be retro- fitted to work with other seatposts.