Golf Monthly’s Callaway Great Big Bertha Epic drivers review – technical editor Joel Tadman tests both new models using the GC2 launch monitor

Product Overview

Overall rating:

Callaway Great Big Bertha Epic drivers


  • Seriously impressive distance across the clubface from both models; they feel fast, powerful with enough adjustability to dial in your ball flight.


  • Not everyone will benefit from the extra draw bias of the GGB Epic model


Callaway Great Big Bertha Epic drivers


Price as reviewed:


Clubhouse Golf

Callaway’s showpiece drivers for 2017 may have a somewhat cheesy name, but it has the technology and performance that requires golfers to take it seriously. In fact, the Callaway Great Big Bertha (GBB) Epic and Epic Sub Zero drivers claim to provide a breakthrough in ball speed gains and the latter has even found its way into the bag of Rory McIlroy.

The key new technology is called Jailbreak, which comprises two metal bars behind the face that connect the sole and crown together allowing the face to take more of the load at impact and spring more powerfully. callaway-gbb-epic-driver-jailbreak-tech

RELATED: Callaway Great Big Bertha Epic drivers launched

There are two versions of the driver. The standard Great Big Bertha Epic and the GGB Epic Sub Zero. The GBB Epic is aimed at a wider spectrum of players and features a 17-gram sliding weight in the rear of the sole to alter shot shape while the Sub Zero model has two adjustable sole weights so golfers can choose either high or low launch and spin.


The GGB Epic felt the better of the two drivers, more explosive and less tinny than its SZ counterpart. It also produced marginally the longest carries but with a little tendency to curve the ball to the left (for a right-hander) even with the sliding weight in the rear of the head set into the maximum fade position.

Perhaps there is more draw bias built in – it is the all ability model after all – but that aside, it’s overall performance and user experience was excellent.


However, it was the Sub Zero model that impressed the most. Not only did it provide exceptionally low spin in the ‘low spin’ setting, but it was also generally high launching (a surprising 9° more than sufficed) and offered surprising levels of forgiveness for what is the more ‘better player’ model.

It feels harder and firmer than the GGB Epic but not any less powerful and when you really struck one out of the screws, you certainly knew about it.


Average carries for both drivers was over 275 yards – a noteworthy feat in itself – while the Sub Zero’s forgiveness levels contributing to a high level of accuracy too. I could have upped the forgiveness levels even more by switching the sole weights around but didn’t feel the need to.


If you’re a typical mid-handicap, mid-swing speed player then the standard Great Big Bertha Epic is the one that is most likely to benefit your game, just because of the seemingly extra draw bias and forgiveness on offer. But don’t discount the SZ model straight away, there could well be a setting there that unlocks extra distance through lower spin but without sacrificing off-centre performance.