Senior and regular shaft drivers are two of the main categories that describe the amount of flex, or bend, in the shaft of a driver and other clubs. Writing for Golf.com, Frank Thomas, former technical director of the U.S. Golf Association, cites shaft flex as a major consideration when fitting drivers or other clubs. If you are playing the wrong shaft flex, you are compromising your ability to hit the ball as long and straight as possible.
There are five basic swing flexes. The most flexible shafts are classified as "L" for ladies. Next come senior, or amateur, shafts, which are designated with a letter "A" on the club. Regular shafts, designated with the letter "R," stiff shafts, designated with the letter "S," and extra stiff shafts, designated as "X," complete the list. It should be noted that the L-designation is something of an anachronism -- some women should play R- or S-shafts and some men should play L-shafts.
A senior flex is generally the best bet for a golfer who generates 70 to 79 mph of club head speed. If you are in this category, you need a club with enough bend in it to maximize the amount of distance you can hit your driver and other clubs. A senior shaft is flexible enough to maximize the distance of a slower swinger without being so whippy that you lose control and accuracy.
Regular flex shafts are designed for golfers with a swing speed in the 80 to 94 mph range. A regular shaft flex gives you a medium amount of bend in the driver and other clubs. Some golf companies produce a stiff-regular or firm shaft which might suit your game if your clubhead speed is in the 95 to 100 mph range.
The biggest problem in buying golf clubs with the right shaft is the lack of uniformity between club manufacturers. There are no industry standards, so drivers from two different companies might both be designated with an "R" for regular shaft flex and still be quite different in the amount of bend. Most large golf shops and pro shops can measure your swing speed on a launch monitor, which is half the battle when it comes to buying clubs with the right shafts. The other half of the battle is to test clubs on the range to make sure a manufacturer's designated senior flex or a regular flex actually gives you optimal results.
Jim Thomas has been a freelance writer since 1978. He wrote a book about professional golfers and has written magazine articles about sports, politics, legal issues, travel and business for national and Northwest publications. He received a Juris Doctor from Duke Law School and a Bachelor of Science in political science from Whitman College.