If the ball is impacted anywhere but in front of the centre of gravity of the club head, the club head will rotate during impact. The counter action of the ball is to rotate the other way – like a gear. It requires friction between the club and the ball for the gear effect to happen. If no friction, there is no ‘gear’. – Trackman News
What is ‘Gear Effect’?
Gear effect is the term used to explain how and why hitting the ball off-centre changes the ball flight. When the ball makes contact with the heel and toe it will cause the club face to change the direction it was pointing and will affect the spin, the ball will turn towards the Centre of Gravity. This is because during the impact the ball and face are interlocked like two gears, this is why it’s called ‘Gear Effect’. So if the club’s COG is further apart from the golf balls COG the more gear effect takes place, resulting in ball flights you’re not expecting. It is worth noting ‘Gear effect’ affects Driver and fairway wood shots, the affect dramatically reduces as you go in to your irons and through to wedges.
Why does ‘Gear Effect’ happen?
When we strike the sweet spot of the driver (the middle) the club’s Centre of mass will effectively line up with the centre of the golf ball. This will produce a very direct hit that will produce an incredible amount of energy resulting in a long drive (higher ball speed off the club face). Therefore, this will mean the club will not twist at impact and you should produce a straight ball flight with all else being equal. However, if you strike off centre the force of the ball when hitting the golf head will not run through the Centre mass of the club. This will result in the club head twisting around the Centre of mass, causing the ball to twist in a different direction. The loss of speed off the face will be noticeable too, whether you strike the toe or heel.
For example, a heel strike will result in the club twisting closed and the ball will spin from left to right, opposed to this a toe strike is when the club will twist open and the ball will spin from right to left.
What are the effects of ‘Gear Effect’?
There are lots of different effects that can take place when you don’t strike the centre of the club, For instance, you may notice a regular pattern to your ball flight which will give you an indication whether you are hitting it on the toe or heel of the club. If you strike the ball out of the heel you will typically see that your ball flight will go pretty high, left to right but more noticeably your ball will not travel very far due to the high spin rate. On the other hand, when striking it out of the toe, your ball flight will generally turn right to left quite vigorously, you also might see that your ball runs out quite far on the fairway. This is due to the spin rate being lower than normal because the impact was of the toe of the golf club. So maybe when you are next out on the golf course and you have hit a dodgy tee shot just think about what your ball flight was like, then think about where you might have hit it on the clubface. Having a better understanding of where you hit it on the clubface will allow you to become a better ball striker.
Modern Driver Technology
You may have seen when looking into purchasing a new driver that manufacturers often talk about the Centre of gravity/mass of the driver head. As a rule of thumb the further away the centre of gravity is away from the face can help with reducing the effects of gear effect. Ping for example have always produced high MOI (moment of inertia) drivers, they set the mass far back and away from the club face as this adds forgiveness. Taylormade recently released ‘Twist Face’ this was created to improve club golfer’s off centre strikes, If you strike the ball off the toe, that area off the face is deliberately more ‘open’ (pointing to the right) to start the ball further right and allow it to curve back to the centre of the fairway. Since this has been introduced we have seen it massively improve customers ability to hit more fairways in our club fittings!
This is a representation of how twist face differs from other club faces on the market
How you can put it into practice…
When you are next on the driving range, as mad as it sounds practice hitting some shots out of the toe and out of the heel, this will help you understand where you are striking it on the clubface. You can use specific equipment the allow you to see your strike pattern, during our Technology lessons on Trackman/GC Quad you can’t hide where you strike the ball on the club face as its always measured (as seen below). As you can now understand It’s an important part of improving in golf. You can get an idea of your strike by using face tape (feel free to come find me if you’re at NFGC I can get you some), even using foot spray will give you a clearer insight of where you are striking the ball. Overall, this will help you have a better understanding of where you strike the ball on the club face and it will also improve your ability to hit the sweet spot.
I hope this blog has been useful and interesting but more importantly it will help you understand what gear effect is and how it can affect your golf shots. It is so important to hit the sweet spot with every golf club in the bag to get your desired shot. When you get back out on the course after the lockdown it will be clear to see that you are not on top of your game, so it’s super important to hit the range first. We look forward to seeing you very soon.
I hope you are well and stay safe!
Assistant PGA Professional
Peter Field Golf Shop