Don't leave hacking down that carbon steerer tube to chance and instead, pick up the SG-8 Carbon Composite Fork Threadless Saw Guide from Park Tool. It accommodates carbon steerer tubes up to 1. 25 inches in diameter and ensures a straight cut every time. Specially designed to accommodate wider, carbon specific saw blades, the SG-8 cuts on 1in, 1-1/8in, and 1-1. 4in threadless fork steerer tubes. It also works great when cutting handlebars or seatposts. Simply clamp the SG-8 onto the tube and cut, letting the SG-8 guide the hacksaw blade. The SG-8's non-scratching composite body incorporates steel threads and a steel reinforcing plate to withstand the rigors of heavy shop use. The SG-8 accommodates blades up to 2. 5mm (3/32") wide.