The most frequently asked questions in the seat customising and motorcycle seat business involve Foam. I must say that it is important enough to look into the different options when looking for comfortable seats.
Some custom motorcycle seat sites say foam is very over rated when it comes to comfort due to the technology of today. Those in the seat business are fond of saying their seat is better because their foam is better,  or that closed cell foam is better than open cell foam, and so on. Those that have access to the gel pads and other new ideas to make a seat more comfortable, all say the same and  have their individual opinions what makes it work best.
I will share with you a little about foam. 

Closed Cell & Open Cell

       We use closed cell foam because it is more comfortable in different applications. Not always, though closed cell foam have several advantages, these being the two most important ones for using it in motorcycle seats.

       Closed cell is Fluid proof. Closed cell foam prevents any nasty fluids from soaking in and this is why it is widely used in various applications.  There fore, closed cell foam on a motorcycle seat can be of some help preventing it from getting soaked in the rain. Water can soak into open cell foam if left with a damaged seat cover and has lost it's water proof cover.  

     You will find Less rebound upon compression with closed cell and Open cell foam will push back. The harder you push, the harder it pushes back. Closed cell foam displaces differently. This can be an advantage in the rebuilding of some motorcycle seats to get different levels of comfort. 

 (There are disadvantages with closed cell)

       Heat and water retention  Because closed cell foams have virtually no air pockets in comparison to open cell foams, they tend to be very warm, even hot especially on those hot days on the long rides.We tend not to use this for the top layer closest to the body because your sweat stays under your backside and has nowhere to go. Not recommended for that  great  ride into the blue horizon.

       Shaping can be difficult. Closed cell foams are difficult to shape compared with open cell foam. When I use closed cell inserts, they may be placed on the frame or on open cell foam that can be sculpted to suit the different applications for individual riders.

      I don't claim to to have all the answers when it comes to customising motorcycle seat foam and reshaping. I do think I am better at it than many efforts I have seen in the past,
due to customers previous attempts by others to rectify their problems. I think about each seat when shaping for extra comfort . I know when some one discusses with me that they feel a problem here or a sore spot there. I relate their backside to the comfort I would like on a ride.
When it is comfortable, Fatigue may not be as much of a problem.

The Various Foams I Use