Motorcycles certainly have come a long way from the charcoal-fired, steam cycle that had a frame that was borrowed from the bone-crusher bicycles of the early 1800s. The ride today is certainly a lot more comfortable, and although the shocks and struts of the modern motorcycle help make the ride more comfortable, advances in seat technology also deserve much of the credit. To make the modern motorcycle seat, more than one type of foam is used.
The top layer of the motorcycle seat consists of a flexible, medium-soft foam. This foam is usually polyurethane that is characterised by open cells. Polyurethane foam does come with a variety of densities. Thin, 1.2 cm (1/2 inch) layers of this foam can also be used with 907 g (2 lb) density polyurethane foam as a top layer on the seat.
There are three possibilities for this layer; all of them are characterised by denseness and durability. The first is closed-cell foam that can be made of polythene as well as minicell. It offers great support, and it doesn't absorb water. The second kind of foam is rebond foam. This foam is also open-celled. This consists of many pieces of foam glued together to create a new, solid piece of foam. The last foam used for the bottom layer of a motorcycle seat is neoprene foam. This foam is closed-cell; it can be used as a base as well as a thin layer for the top layer of the seat as well. It is durable and resistant to oxidation and sunlight.
Some motorcycle seats have additional foam that forms an insert for extra comfort. The foam used for this purpose is viscoelastic polymer gel. This type of foam is effective in absorbing vibration as well as shock.