Too many modern mountain bike stems sacrifice strength & torsional stiffness for a few grams of saved weight. The Thomson X4 is the leader in strength & stiffness. The Thomson X4 stem means that you can realize the benefits of stiffer forks & stiffer 31.8mm bars. X4 offers precise steering, tracking & more control while riding, all wrapped up in a beautiful design. Certified to: EN 14766 2006 MTB & DIN CERTCO: 2006 MTB The Thomson X4 is stronger & 30g lighter than the Thomson Elite 25.4mm mountain stem. It features a traditional steerer clamp that is shaped to save weight & to be knee friendly. X4 is absolutely the best combination of strength & weight available. Thomson stems are the strongest in the industry, meaning enduro & downhill riders can run Thomson confidently. The stem is one piece of solid 7000 series Aluminium extruded billet precision, machined by Thomson in Macon, Georgia. It’s built & tested to the same standards as aerospace parts & it’s the best stem for all-around mountain bike & cyclocross riding. Precise steering, tracking & more riding control. Traditional, knee friendly steerer clamp. One piece 7000 series Aluminium. Machined by Thomson, in Macon, Georgia. Available in Black or Silver. Available from 40mm to 130mm lengths. 40-60mm stems are available in block style only..