Golf is one of the most technical sports in the world, and this doesn’t just extend to the actual technique of the swing, but also the equipment.

Golf balls and clubs come in a range of configurations, all of which can have huge ramifications on performance, potentially increasing your accuracy and distance considerably.

However finding the right equipment isn’t easy, and there is a lot to know about the different aspects of golf. Club length, shaft material, and shaft flex are three of the most important aspects, however many people have no idea just how important they are, or that they exist at all.

Using the incorrect club length or flex can stunt your performance in many ways, and can even affect your technique building bad habits into your swing as you try to compensate for a poor setup.

In this guide, we’re going to look at what flex is, as well as the various different types of flex available, and what you should use depending on your handicap and experience level, age, strength, and other key factors that determine how useful a certain flex will be for you.

What is flex?

Flex refers to the amount of bend a golf shaft can achieve as the forces of a swing are applied to it. 

The forces a golf club and the shaft are subjected to can vary according to many factors, giving each golfer their own particular type of swing, and thus different requirements for the flex their golf clubs should use.

There are several different ratings of flex used by most golf club manufacturers and brands, however, many golfers are totally unaware of these or how important they are to improving your game.

Let’s take a look at the different types of flex available and their characteristics.

What different kinds of shaft flex are there?

There are several kinds of flex available, and although some are more popular and common than others, they can all be useful depending on the particular golfer’s needs.

The range of different flex types are;

• Extra Stiff (XS)
• Stiff (S)
• Regular (R)
• Senior (S)
• Ladies (L)
• Junior (J)

These broad categories are used to give golfers a better idea of what to look for, however not all brands will use the exact same specifications for each bracket of flex, meaning there can be some significant differences between these, making it even more difficult to determine which is best for you, depending on the brand.

One brand’s regular flex may be equivalent to a different brand’s firm flex, and so on. It’s important to research this carefully when looking for a particular brand or type of flex to suit your needs.

How do I know which flex shaft to use?

Working out what flex you need can be incredibly challenging, even for very experienced golfers. 

Golf clubs are also a significant investment, so making the wrong choice can really cost you, so it’s best not to take a punt or risk purchasing something that doesn’t suit you.

The first thing you should consider doing is visiting a golf shop to get a club fitting. A shop pro should be able to analyse your swing and give you some recommendations about the flex you need. 

The main thing they’ll be looking at when they do this is swing speed. Swing speed is the biggest factor in determining which shaft you should choose.

Generally the faster the swing the stiffer the flex of shaft is required.

Club	Clubhead speed	Recommended shaft flex
Driver	> 105 mph	Extra stiff
6-Iron	> 92 mph	Extra stiff
Driver	97 – 104 mph	Stiff
6-Iron	84 – 91 mph	Stiff
Driver	84 – 96 mph	Regular
6-Iron	75 – 83 mph	Regular
Driver	72 – 83 mph	Senior
6-Iron	65 – 74 mph	Senior
Driver	< 72 mph	Ladies
6-Iron	< 65 mph	Ladies

But it’s worth bearing in mind that your swing speed may not correlate perfectly throughout your bag.

Just because you need a stiff shaft in your driver, ths doesn’t necessarily mean you need them in your irons. For that reason we’ve included both a driver swing speed and mid-iron swing speed in the table above. Let’s also run through the different shaft options below.

Extra Stiff Flex

Elite level golfers with good technique will generally be the ones who fall under this category,

If you’re someone who consistently drives the ball around 300 yards off the tee (or near to this) an extra stiff flex will likely be a good choice for you as your swing speeds are very high and would benefit from the additional stiffness your swing creates.

Extra stiff flex in irons are slightly rarer than they are in drivers. You’ll need to be a very good ball striker to warrant them in your irons.

However, be prepared to pay top dollar for extra stiff shafts in either a driver of a set of irons. Whilst regular and stiff shafts are readily available in stock clubs, extra stiff shafts are harder to come by and will generally require custom orders and upgraded costs.

Stiff Flex

If you’re hitting somewhere around 250 yards consistently off the tee, then a stiff flex driver would likely suit you. Your swing speed is fast enough that a regular shaft would be too flexible for you and probably result in a few wide misses.

It’s common for stiff shafts to be an on-the-shelf option for both irons and drivers.

Regular Flex

If you typically hit between 220 to 250 yards off the tee, then a regular flex club will likely suit you best. They are most appropriate for most mid to high handicap golfers, and even some who are more experienced but getting older and don’t quite generate enough speed to warrant a stiff shaft.

For men who are total beginners, a regular flex club would be the place to start for your first set of clubs.

Senior Flex

Senior flex shafts are designed to help golfers who are generally a little older and struggle to swing the club over 83mph with a driver or 74 mph with an iron. Senior flex shafts are more common in irons and generally require a custom order as they aren’t a readily available on-the-shelf option.

Ladies Flex

Ladies flex clubs are naturally made to support women (and also junior golfers) with their slightly slower swing speeds. Generally, ladies flex shafts will come in specifically designed ladies golf clubs and aren’t readily available as stock options in most golf clubs.

Does shaft material affect flex?

Shaft material can affect flex somewhat, however, whatever type of shaft is in your club will be tweaked to deliver the flex stated on the shaft.

Steel shafts – are more common in irons (and used very rarely in woods), but are still available in a range of different flexes. They are heavier and cheaper than graphite shafts.

Graphite shafts – are lighter than steel shafts and are more common in woods, hybrids and drivers. Due to the weight they are also particularly suited to beginners, seniors, juniors and ladies golfers in sets of irons. They can help golfers who struggle to use heavier steel shafts and need help generating extra speed.

Final thoughts

The flex you need for your golf clubs really depends on your swing speed, age, strength, and experience level, meaning there are a lot of variables that can affect your choice and what works for you.

Don’t be afraid to test clubs out before you buy and get a feel for what suits you, as a golf club is a significant investment that you’ll want to get the best out of for a long time, helping you to reach new distances and potentially moving your handicap down.