Ribble r872 carbon road forks these forks are only supplied when you also order ribble r872 carbon frame these forks only fit frames with a 1 18 1 12 head tube and require a 1 18 1 12 r872 headset weight 400g all carbon forks with a carbon steerer require a specialist expanding stem cap we recommend the 52mm itm version failure to use this will result in damage to the carbon steerer itm carbon 1 18 expanding stem cap