Spirgrips improves the performance by removing pain in the hands, blisters and tingling sensations. It allows a better pedaling efficiency, a more aerodynamic position on flat roads, it is more confortable during long ascents, and you have a safer access to your water bottle during uneven areas. These are my initial conclusions. People have noticed Spirgrips on my bike and would like to order some. A version made out of carbon would be great for competitors.