Tune's Gum Gum is the lightest expander available at only 9 grams. This simple design comprised of mainly silicone will allow you to drop weight while also protecting your carbon fiber steerer tube from the stresses often induced by overkill expanders. With most 'original equipment' expanders weighing in over 30 grams, you can expect significant weight savings by using the Gum Gum.
9g
*Note: compatibility is limited to fork steerers with inner diameters of 24.0-25.5mm.