Splitting parts down the middle isn't usually a great way to make them stronger, but Renthal's Duo Stem isn't your usual bike part. Renthal's motocross background gives it a different perspective than most MTB part manufacturers, so maybe the uniqueness of the Duo shouldn't be surprising. By crafting it from two parts of CNC-machined 6082 aluminum, Renthal was able slim the weight down to a weensie 124g without any loss of strength compared to more traditional stems. Slap it on your 31. 8mm diameter bars and get to rippin'.