Zipp engineered its Tangente Tube with the goal of making it more stable overall, which it did by adding a lightweight aluminum Presta valve and reducing rotational mass at the valve body. By saving weight on the aluminum valve, Zipp was able to thicken the butyl walls of the Tangente to 0. 85mm, increasing their durability and hopefully decreasing the time you spend changing flats on the side of the road.