Aeffect stem aeffect 35 stem is a new design that brings the advantages of 35 to the xctrail crowd at a mid level pricepoint while maintaining a refined race face look forged and machined from 6061 aluminum interlocking 4 bolt bar clamp secures your bar and distributes loads away from bolts and into the body specification for xc trail use 6 rise 35mm bar clamp diameter 39mm stack height 155g