The Ribcage has been one of the only rims to have true design breakthroughs in the last few years, since its introduction the competition has scrambled to catch up but still remain a poor copy, so if it doesnt say G-Sport on the rim, don't expect it to perform like a G-Sport rim. The Ribcage is a light weight rim that can take anything you throw at it. With the ribcage the spoke holes are re-enforced with patented ribs that support the sides of each spoke nipple and eliminate the possibility of nipple pull through under even the highest loads. The rim also features cross-over-spoke lacing, where each spoke goes from one side of the hub to the opposite side of the rim for an increased angle and therefore increased lateral strength. The outer walls are extra thick to protect against case dents, while the other walls are extra thin to keep it light. The entire design revolves around the use of a proprietary high strength aluminum alloy made specially for us in an on-site foundry . At 500 grams, the strength to weight ratio of the Ribcage cannot be matched. The 36mm width and 18mm height are also major factors in the design, spreading out the impacts and maximizing resistance to pinch puncturing. GSport offers rims in HARD anodized finishes rather than the decorative anodizing used by most companies. All of these advantages create the premier rim, but do effect the cost. TECHNICAL SPECIFICATIONS - Sizes: 20" Only - Drillings: 36 and 48 - Weight (Hard Anodised): 500g /17.6oz - Weight (Chrome Plate): 540g / 19oz - Width: 36mm ERD: 389