The golf club design during the past decade has undergone considerable evolution, more specifically longer distance, lighter weight, higher swing speeds and dampened vibrations, has pushed golf club builders and manufacturers to higher challenges. Many of which have been answered through new and advanced golf shaft designs, materials and manufacturing processes.
Some of the best results for the finest performing golf shafts were not obtained by one of the known golf shaft manufacturers, but by a small research and development firm on the West Coast. Carter Penley, with a graduate degree and 35 years experience in composite materials, is the head of the P.R.D. Group. His firm is specializing in the design of structural tubes using fiberglass ("E" type and "S" type), carbon fiber, Kevlar, boron and combinations thereof. His client list include the U.S. Government, Ford S.V.O., Chevrolet Valve Train Group, Pontiac, Harley Davison, San Diego Zoo and more specifically the sporting good industry.
The main parameters dictated for his research on golf shafts were the following:
1 Run a variety of tests on all golf shafts in the target group to complete and compile and comprehensive analysis to specifically include strength, durability, and playability.
2 Design golf shafts that incorporates the best possible features obtained from the empirical data and user input and improve on the desirable attributes and design out the less desirable attributes.
3 Develop a golf shaft that defies the laws of physics; squaring up with faster recovery at impact and with a wider range of player controlled swing speeds than any other shaft on the market today.
Combining aerospace technology and his extensive experience in composites, Carter Penley incorporated new and innovative materials, resins processes and tooling in his new generation of golf shafts. The fiber had to exhibit the characteristics of high modulus for torque and stiffness requirements and also incorporate the high strength properties to sustain the high compressive double kick loads that would be generated by the very fast head speeds that would be generated in todays game.
Because of very high golf club head speeds, micro-mechanics became base material specific, now requiring the selection of materials not generally used in the sports industry. To insure high fiber fraction (volume), a very-fine (nano-like diameter filament) high density fiber exclusively used by the defense aerospace contractors was selected. This material and design required a lower resin content to insure a low shaft weight yet maintaining the torque and stiffness levels without inducing brittleness. Micro-mechanics of the design also dictated that the standard sport resins used throughout the industry most likely would not structurally accomplish the task, therefore, Penley selected a high strength toughened resin specified for aerospace/flight hardware component design.
To finalize the development of a new and advanced family of golf shafts, Penley developed all new shaft patterns and mandrel designs as well as upgrading manufacturing processes to accommodate the advanced aerospace materials.
Last but not least, is the overriding reason for the success of all golf shafts designed and manufactured by Carter Penley is that Mr. Penley manufactures100% of all his golf shafts and other composite products in the U.S.A. and is one of the few - if any, owner, founder and designer that is full time at the manufacturing plant and on the floor of the manufacturing facility tuning the manufacturing process and is personally involved in making course corrections and solving manufacturing problems on a daily, if not hourly basis.
If you are not purchasing a golf shaft DESIGNED AND MANUFACTURED BY CARTER PENLEY, YOU DO NOT HAVE AN AUTHENTIC HIGH QUALITY PENLEY GOLF SHAFT BACKED BY THE FULL FAITH OF CARTER PENLEY.
About Carter Penley 
