Nukeproof sam hill series direct mount stemprecision cnc machined from high grade aluminium the nukeproof range of stems has been engineered for the optimum balance of light weight and stiffness without compromising structural integrity the direct stem is compatible with the industry standard 4 bolt top crown mounting pattern and is suitable for use on all matching dual crown dh forks including rockshox boxxer marzocchi 888 2012 onwards fox and bos features bar clamp 31 8mmlength 45mmri