Fox Unveils Awesome ‘Drillium’ Promo for New Superlight Dropper PostDrillium. Fox just released their Transfer SL (super light) dropper post and to celebrate, they made the very cool looking photoshop Drillium post you see above. The lightest Transfer SL post, with 50mm of travel, and a 27.2mm diameter post, weighs just 372 grams. The popular Rock Shox Reverb dropper weighs well over 600 grams, for instance, depending on size. You can get the Transfer SL in the posh Factory build with Ti parts and that slick gold Kashima coating for about $400.