Saddles can either make riding a mountain bike enjoyable, or a pain in the butt. The two factors that come into play with a saddle are weight and comfort. Of course you want your mountain bike to be as light as possible to minimize the effort put into riding. You also want to enjoy the ride, so comfort may be at the top of the list. Which ever one is more important to you, is how you will decide on the right saddle for your mountain bike.