Introducing the world’s first tapered and welded, alloy 31.8mm clamp BMX handlebar. Box One™ Alloy Triple Taper Handlebars are stiffer than our carbon fiber bars and nearly as stiff as our Box One™ Cromo handlebars, making them an ideal choice for up-and-coming BMX racers and diminutive weight freaks. They fit all 31.8mm bar bore stems.