I have a red and turquoise tri suit made in 1987. It has a thin pad made of fabric as opposed to real or fake chamois. The fabric tri suit pad is much quicker drying than a cycle shorts pad.
The triathlete has to swim first and gets onto his bike while still wet. His body weight on the saddle will squeeze out some water then his body heat will dry out the suit and pad.
The suit has to be comfortable while running in the third section of the race, a thick pad would get in the way of free running action. My tri suit has zips up the sides of the legs allowing extra fabric behind the zips to open up making the legs looser for the running section.
Me in 1987 Canterbury Triathlon bike section:
http://five.flash-gear.com/npuz/puz....874&k=60366358
Me in 1987 Canterbury Triathlon run section:
http://three.flash-gear.com/npuz/puz...752&k=19919886