OUO MTB Stem 31.8mm Handlebar Stem Riser Short 45mm Aluminum Bicycle Bridge For Downhill Racing Mountain Bike Bicycl Accessori OUO MTB Stem 31.8mm Handlebar Stem Riser Short 45mm Aluminum Bicycle Bridge For Downhill Racing Mountain Bike Bicycl Accessori. Sale price : $9.65 Category : Sports & Entertainment