Area proves to be a faulty explanation. We are not compressing the bladder but the gas behind the bladder. This is a fixed amount and we compress the exact same number of gas molecules whether the side compresses the tops or all of them are compressed. For this reason the force properties of the shock are not a function of surface area. Importantly it was also noted that the rod charge was also higher on the bladder shock, this would indicate that the total volume of gas was down and that the bladder actually results in a decrease in effective diameter which has a significant impact on total rod charge.