what are bike seat made of and is the material renewable?

Answer 1

Usually steel rails, then a plastic seat pan topped by a thin layer of high density foam and then a surface fabric.

Some saddles consist of a piece of leather stretched over a steel frame.

Answer 2

Depends on the price range, but usually steel rails, a plastic seat pan, a thin layer of high density foam, and then a cover of either leather or some synthetic fabric. More expensive saddles can have carbon fibre in the pan and titanium rails. Retro saddles like Brooks hasn't got a pan but instead rely on a thick piece of leather stretched between the ends of the rails.
Bike saddles usually have two metal rails, then a plastic pan, on top of that a foam/gel pad, and on top of that a cover that can be either real leather, cloth, or a synthetic leather. There are also saddles made of thick leather stretched over a metal frame, carbon fiber saddles w/o any padding, and BMX/street/dirt saddles that are plastic w/o any cover.
Unless it's on a recumbent bike, most people call them saddles as opposed to seats. They can be made of several different materials, the most common being steel rails, a plastic pan, a layer of foam rubbing and then a top layer that can be either skin, fabric, or some sort of synthetic leather. The lightest and most expensive saddles use carbon fiber throughout. Not very comfy but they sure are light. Retro saddles like Brooks use steel rails, sometimes springs and then thick leather for the actual sitting surface.

Answer 3

Birgit.