Mizuno JPX 850 Driver Review

The incredible technology of recent times has provided companies with a backbone with which to build upon, and Mizuno is a prime example: recreating their Fast Track design for greater, more specific customization, providing a large loft variety in a single head, and introducing a fantastic color scheme with a quality shaft leaves golfers wanting to spend plenty of time with the JPX 850.


From Mizuno

Design Details

In 2007 Mizuno introduced a sliding weight system called Fast Track – to alter a driver’s draw/fade tendency. Mizuno has now evolved this breakthrough technology to also be able to customize spin rate and launch angle in the JPX-850 – helping all swing speeds achieve maximum possible total yardage. A massive playing profile with a low and deep extended weighting system launches the ball into an optimized, low spinning orbit – from whichever QuickSwitch setting you choose.

The piercing blue JPX-850 uses twin 8-gram weights which can be located on either the central sliding rail, or two lateral slots. With 10 unique settings, players of all head speeds can dial in their perfect launch and spin.

In combination with Mizuno’s Quick Switch shaft release system, the JPX-850 also offers lofts from 7.5 to 11.5 within one head for the ultimate in adjustability.

The JPX-850 head is a compact, powerful 440cc Titanium driver that utilizes a Rebound Crown to maximize ball speeds for unmatched distance.

Tech Spec

  • Fast Track: 10 unique flight settings (4 neutral, 3 draw, 3 fade) to dial in launch and spin for increased distance.
  • Quick Switch: 8 loft settings from 7.5 to 11.5 degrees.
  • Rebound crown: Rounded crown flexes at impact for explosive distance.


“The genius of the new Fast Track is that it adds the dimension of launch angle and spin rate. Now the player is truly in control of maximizing all aspects of their ball flight off the tee.”

Chuck Couch – VP of Product Management

First Impressions

When you take the time to read about the JPX 850 driver by Mizuno, it is very difficult to not be intrigued by the level of customization.  The most visible change is the Fast Track technology (which will be discussed in depth later), with the weight ports being either populated by an 8 gram weight, or void of anything.  Naturally, the screws are loosened and the weights are interchanged, building greater intrigue for the range and course.


When it comes down to looks, the JPX 850 is quite stunning.  Akin to the standard Mizuno blue, the crown offers a vibrant and fresh blue look to break the monotony of neutral colors present in today’s driver marketplace.  Accented with white decals and the Mizuno logo as a sight line, it is a very appealing sight when addressing the golf ball.  This is complemented perfectly by the white and blue Fujikura Motore shaft and the stock Mizuno M-31 grip.


Quick Switch Adapter

The adapter system of the JPX 850 is quite massive in flexibility, ranging from 7.5 degrees of loft all the way to 11.5 degrees of loft.  This creates opportunity for customization from a single head, which can be a major benefit for players who like to tinker with their settings.  Despite the freedoms that this design element offers, it comes at the cost of face angle, introducing a more closed face as the loft is increased from 9.5 degrees, and introducing an open face as the loft decreases from 9.5 degrees.

By taking advantage of this setting, testing proved that a stock center face contact swing with the setting at the extreme low loft of 7.5 degrees actually introduced a fade into the flight pattern of the golf ball, and increasing to 11.5 promoted a higher draw.  While this will be discussed later in the review, it made for an interesting balance between the Fast Track concept and the Quick Switch adapter.


While loft options are limited to 7.5, 8.5, 9.5, 10.5, and 11.5, the Quick Switch adapter also includes upright lofts in 8.5, 9.5, and 10.5 degrees.  This is very beneficial for golfers with a steeper attack into the ball, and will help to promote a straighter flight if a fade is present on the standard setting. 

Fast Track

Despite the color of the JPX 850 driver being the standout when first eyeing the club, Fast Track technology produces a serious amount of intrigue.  While there are plenty of drivers on the market with weight ports that can be adjusted around the head, the weights in the JPX 850 can be removed completely in favor of a different slot.  It allows golfers to add or take away all the weight to create larger change in shot shaping.

There was an obvious change in flight moving weights between the toe and heel ports, yet testing showed minimal changes in spin rates between the three settings that make up the Fast Track in the center of the club head.  While this is an advantage to make these slight changes, testing seemed to suggest they would be more viable for golfers seeking slightly better numbers rather than those golfers hunting for large adjustability changes in the spin rate and launch angle of a driver head.


How They Work Together

Despite the quick switch adapter and the Fast Track technology being discussed separately, they do well to work together when trying to generate the perfect flight.  During testing, as preferences lead to the lower end of the loft spectrum on the quick switch adapter, utilizing a combination of the upright setting along with a weight in the toe weight port promoted a much straighter flight than weights combined in the Fast Track.   What this should lead to is a counter effect that will benefit every style of swing, which was welcomed each time a change was made to the loft or weights.



The driver spectrum for sound is quite wide across the golf industry, and testing seemed to place the JPX 850 right in the middle.  Certainly not muted in any way, but by no means overly ‘loud’ or high pitched.  The sound seems to be quite consistent across the center of the face with pure/flush contact, and is only slightly toned down as you move towards the heel or toe.  Certainly this slightly more dull sound occurs as contact travels lower on the face and towards the heel.


The overall forgiveness of the JPX 850 was quite good, with respect to how the weights were positioned on the bottom of the head.  Flight consistency was easily achieved through rounds during testing, and while left pulls were unavoidable for any head, the weaker contact seemed to maintain a quality ball flight with reasonable distance losses.  There was a marginal increase in overall head stability on mishits with the weights on the heel and toe slots rather than down in the Fast Track slot, however it was nothing outlandish in comparison.  At 440cc, the expectations of forgiveness were met and exceeded, especially on testing scenarios where a little bit more was attempted to be had out of the head.

Distance and Flight

While it is not realistic to launch the JPX 850 into the category of “longest” or “fastest,” the driver absolutely maintained a better than average carry total in most conditions.  Combining the ability to adjust spin, loft, and flight settings across the spectrum, it would be of little surprise to see a high percentage of golfers find an ideal setting that meets their own distance expectations.


Paired with the Fujikura Motore Speeder VC 6.3 Tour Spec shaft, the profile is that of a mid to mid-high launch depending on the setting selected, matching the expectations provided by Mizuno.  The flight generated is a relatively flat trajectory that maintains peak height for a decent distance.  Not unlike the driver sound, this shaft pairing introduces a very predictable feedback that promotes confidence on great shots and clarity on weaker timed strikes.

Parting Thoughts

Mizuno has created a highly adaptable driver that can and will suit the golf game of a large percentage of handicaps.  With how many settings are present, golfers can tinker with settings until they find the perfect combination of spin and launch, yet all the while altering their preferred ‘stock’ shot shape.  While each of the three adjustment capabilities may come up short on expectations, it is their combined profile that suits a swing so well.  This has all been accomplished in a slightly more compact and highly attractive blue driver head, while maintaining that Mizuno look.  For more information on the Mizuno JPX 850 driver, visit www.MizunoUSA.com.

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Dan E.
Dan Edwards is a THP staff writer that currently resides in southern Ohio. He is a low index player that has a long-held love for taking in and sharing knowledge about golf equipment.