If you're keen on importing the new gravity standard of 35mm bars to your XC or trail rig, then Race Face's Aeffect 35 Stem has you covered. Its 6061 aluminum body is lightweight and designed for single-crown forks, but it lets you replace your oversized 31. 8mm bar with an over-oversized 35mm model. The overall expansion of bar and stem does come with a slight weight gain, but we think the added stiffness and reliability of a reinforced cockpit is worth the few extra grams -- especially considering the wider handlebars we're seeing on mountain bikes these days.