Super light weight in 31.8 mm.The legendary Syntace F99 stem now in 31.8 mm handlebar clamping diameter - the F109. For road and MTB use.If 31.8 is being used for the handlebar clamping diameter then the rest of the stem should be made equally as stiff and strong. A thicker stem tube is used and this oversize diameter is kept throughout the stem to the clamp area.Unmatched combination of new, high-strength and forgeable aluminium alloy and real 3D forging. The result: The lightest stem in 31,8, which is still totally bombproof and as stiff as other stems that weight 160 g. Also suitable for aero bars.Light weight Titanium bolts - standard.