All Lenz Sport Mountain bike frames are hand made from the ground up, right here in our factory in Colorado. We use superior grade, American aluminum for every frame. All of the parts that go into the fabrication of each frame are CNC machined in-house, including dropouts, cable guides, head tubes, yokes, gussets, and more. We design our frame tubing to maximize strength, stiffness, durability, and lightness. All Lenz Sport bicycle frames are the lightest in their class, when compared to other aluminum frames, and the exclusive Lenz geometry means you will feel comfortable riding in any terrain you can dish out.