The XR-200 is KinLin company's lightest road rim, and one of the lightest aluminum rims on the market. The XR-200 features a boxed aero cross section for added strength - not the most aerodynamic rim on the market, but ideal for use in a climbing or weight-conscious wheels. Extruded from a superlight Niobium-Aluminum alloy and joined with a high quality pinned joint. Finish work on these rims includes a high gloss anodization and machined sidewalls. For these rims, we do recommend higher spoke counts (i.e. 24 front, 28 rear) for riders over 55kg (120 lbs), and do not recommend them at all for riders over 85kg (190 lbs).