Easton Havoc Lo Riser 750mm Carbon Handlebar. Go big with confidence when you've got the Easton Havoc Lo Riser Carbon Handlebar on your mountain bike. You're not going to find a stronger handlebar that accommodates a 31.8mm stem, plus it's nice and wide at 750mm and super light at 235 grams. The Havoc Lo Riser Carbon is lighter than most all mountain bars currently on the market and, thanks to lab testing and ride testing on the bikes of top gravity riders, it's even stronger and tougher than much heavier alloy bars. Constructed of Easton's EC90 carbon fiber, Easton makes judicious use of their TaperWall technology to maximize strength and minimize weight.