Modern bars are designed to NOT flex or bend. Aluminum will fail if subjected to repeated "bending" cycles, so aluminum bars are designed to be flex free. In theory, a thin, light carbon bar could be designed to be "flexy", but that would increase the chances of failure, something a good designer would avoid.
Steel tubes can flex forever without failure, so if someone wanted to design a "flexy" bar, steel is the material they would use. But, today, steel bars are used only on either "cheap" bikes, or on track bikes, and both of those uses call for heavy-duty bars.
If you want to reduce road shock, the easiest way is to buy a bike with a long wheel-base, such as 41 inches or 42 inches, with a steel fork that has the "reverse J" bend near the hub. In other words, you need a road bike from forty years ago.
With a "modern" roadbike, with its 39 inch wheelbase and "straight leg" fork, the best ways to reduce road shock are to move to 28mm or 32mm tires, and use a gel tape on the bars. And, several companies are making gel pads to put under the gel tape...sort of a "jello" bar.
On longer rides, using gloves with gel pads, and using a relaxed grip on the bars is helpful. Many folks have their hands way too tight, and that will cause discomfort over hours of riding.
Wrist pain usually means you have too much weight on your hands. Raise your bars so that the top of the brake hoods are level with the top of the saddle. That higher bar position will eliminate wrist pain, neck pain, back pain, and crotch discomfort.
If you and your bike have a combined weight of less than 190 pounds or so, you can inflate your tires to 10% or 20% less than the "Max PSI" stamped on the sides of your tires. So, if your tires have a "Max PSI" of 100 PSI, try 80 PSI in front, and 90 PSI in back. The slightly lower PSI level enables the sidewalls to flex slightly over rough pavement, and the tires will absorb much of the shock before it reaches your hands and body.
Last edited by alanbikehouston; 08-10-07 at 11:01 AM.