It is true the GasGas seat is very thin!! Here is the answer to your monkey butt.
The foam is an inch taller giving you a very flat riding position and making sitting to standing that much easier on your knees!
The seat foam is high density, so it is comfortable, but you wont just sink into it like conventional foam.
These seat foams suit all 450/515/200/250/300cc 2007 - 2011 GasGas bikes.
Click here for tall gripper seat covers to suit: http://www.mainjet.com.au/product_info.php?cPath=36&products_id=172&osCsid=b64ce2c0abdd8c6a6c9231bf6ab459e9