The Gsport Birdcage rim has a big and chunky bead to help reduce the chances of pinch puncturing or flat spotting the rim, but at same time the tiny hollow cavity inside it helps keep the weight right down. The rim also features a cross-lacing design to increase lateral wheel strength, and a offset value hole to help with strength in a common weak spot on aero style rims, this also makes it easier to fit a pump to the valve. This rim has a weight of just 408g (14.4oz) it outperforms most rims weighing 20-30% more, and the weight saving from the rotational mass of the wheel feels fantastic.