The Hull: the hull can be realized in various materials, the most popular is nylon, but has since spread from nylon reinforced with a certain percentage of carbon fiber, carbon fiber hull is now spreading.
The hull is stiff nylon, cheap but not very light. The combination of carbon with nylon to increase the stiffness, the ability to absorb vibration while increasing the development cost. The carbon hulls have the advantage of rigidity, low weight and ability to absorb vibrations, but are penalized by the high cost.
The choice of hull: hull is what most determines the characteristics of a saddle. Exclude hulls only nylon, now reserved for low-end products. Best nylon and carbon hulls and still hammer ful carbon hulls. A good hull, then, must be hard, especially in the rear, where rests the buttocks. For optimum performance the entire surface of the hull should be rigid, from the tip to the back. But this very limited comfort. Many hulls have a central less rigid and more flexible, this allows for some decompression of the genitals and more comfort on bumpy. Some hulls have holes decompression for the perineum. A good forum for relief must be broad and long, in theory it should have a good opening for almost the entire length of the saddle, but be careful, because a large opening, then backing off in the buttock that had less space to distribute your body weight is numb before. Holes are small and limited in practice negligible. For the time trial and triathlon is good to have a short and rigid hull also saddle points. Women should have a hull off the back, while even those who want a comfortable saddle should pay attention to the width of the saddle, the broader the more comfortable because the weight of the body have on ventilation greater. If the rear is good which is wide, the front must be close to allowing the legs to stay close and not collide with the saddle itself. The length of the saddles is influential and important for those who often travel in the saddle or have a stretched position on the vehicle (preferably a long saddle), while those who remain centered in the saddle they can choose a short. Another aspect to consider is the surface of the hull, if it is flat for ease of movement and efficiency of pedaling, but compresses the genitals and is less comfortable, is dated to the athletes and those with good posture in the saddle with the pelvis remaining perpendicular the plane of the saddle. Other hulls may have a pattern which facilitates the positioning angle of the pelvis, helping to reduce pressure on the perineum. Hulls are preferred for those who have good flexibility of the trunk, looking for a high comfort and good reduction of pressure on the perineum, although at the expense of reduced ability to move in the saddle.