THE ULTIMATE RACE SHORT You know Castelli can make a great bike short. This one doesn't disappoint, thanks to amazing fit, the quick-drying Instadry fabric that gives compressive muscle support, and the renowned KISS Tri seat pad. New GIRO4 leg grippers hold the longer legs in place without riding up. For the swim we've made the short smoother through the water, and the back pocket will lie flat to avoid catching water. The SnapLock closure clips to your Castelli top to keep it from riding up. On the run, the short basically disappears. The KISS Tri seat pad is thin enough you don't really notice it, while the Instadry Speed fabric provides the support you need, and here you'll appreciate the extra support layer in the front.