Youth Series for Youth With the right start, cycling can be a lifelong pursuit—They know it's true because that's how it worked out for every one of them at Jamis. They know just how important that first bike can be, and that's why their kids' bikes are some of the most important bikes they design and build—because if they've done this right, that first riding experience will be so fun it'll carry through for the rest of their lives. Sturdy Alloy Lightweight and strong 6061 series aluminium tubing, featuring over-sized & tapered tubing for increased frame stiffness. Top Tube Cable Routing Running the cables up under the top tube keeps cables and housing out of the muck for more precise and reliable shifting performance. Replaceable Derailleur Hanger Because it's much easier and much less expensive to replace a derailleur hanger than it is to repair or replace a frame, this frame offers a replaceable derailleur hanger designed to yield in a crash before the frame does.