Callaway Great Big Bertha Epic & Epic Sub Zero Drivers

GBB Epic

The Callaway Great Big Bertha Epic driver has been around for a little while now and it keeps coming up as one of the best drivers out there, in both the base form and the Sub Zero form.

The GBB Epic introduces new technology as well as retaining design features from previous models:

  • New: Jailbreak technology and more Carbon to free up weight
  • Speed Step design on the crown to reduce drag and increase club head speed
  • An adjustable hosel and moveable weight (or 2 weights that can be swapped to change the MOI in the Sub Zero model) to give the golfer adjustability to fit their swing

The Sub Zero version is for the high spinning golfer which may suit the big bombers out there. It provides less adjustability than the base Epic but the design still provides the forgiveness that is desired by most golfers.

All of this technology supports the face to maximise ball speed transfer across the face, effectively creating a larger sweet spot. And the Epic delivers with even more speed than its predecessor the XR, with Callaway talking about a 2mph ball speed increase for a 100mph swing speed. It is also a very forgiving driver that allows the player to move 17g of weight around the back of the club to manage their ball shape and even out their hooking or slicing tendencies.

Jailbreak and Triaxial Carbon

Every driver designer aims to give themselves options for how they use weight to create the most forgiving and user friendly club possible. A certain amount of weight is going to be used to build the body and the face, and it is essential that the body and face are strong enough. Callaway have developed Jailbreak – a pair of 3g titanium pins that join and reinforce the crown and sole to reduce the amount of distortion during impact. This reduces the amount of material required to build the face and body of the driver as they take less strain.

In addition Callaway have increased the amount of carbon used to 52% of the body of the driver. Overall they have saved a huge amount of weight that they have used to include a weight and slide in the back of the driver for increased adjustability while improving face stability – an impressive feat.


Both clubs use the Optifit adjustable hosel system. This allows the player to:

  • Adjust loft 1 degree lower or 1 or 2 degrees higher
  • Build in a Draw bias or a Neutral bias

The GBB Epic has a 17g weight at the back of the clubhead that can be moved anywhere within the track to vary the shot shape characteristics of the driver. Slicers can set up some draw bias and hookers some fade bias to straighten up their normal shape. This is a useful feature for high and mid handicappers who consistently put too much shape on the ball.

The GBB Epic Sub Zero has 2 weights that can be interchanged to move the Moment of Inertia (MOI) back to increase spin and forgiveness or forward to reduce spin and increase workability (the ability to draw or fade the ball on command).

Speed Step

The GBB Epic continues to use the Speed Step design that was introduced with the VR line. These shapes improve the aerodynamics of the club to minimise drag and maximise clubhead speed. And as we know clubhead speed equates to ball speed.

Review findings from across the web

Buy Online

The Callaway GBB Epic range is available from
For US and International Buyers For Australian Buyers
Fairway Golf Online Amazon Australia


If you have any questions or comments or your own thoughts on the club please leave a comment below.

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