With a growing trend for high-MOI mallets on tour, putter designer
Guerin Rife set himself a challenge to design a putter with double the
MOI of many of the most popular high MOI head designs on tour.
“I noticed more and more lately that many players on the PGA Tour are opting for high MOI oversized putter head designs,” explained Rife. “They have to stand over a 4-foot putt worth $200k to $1m that will change their life. The pressure can be paralysing.”
The nerves don’t have to take over too much for an extremely costly miss, so highly stable putter designs that help to counter some of the potentially damaging effects of pressure and nerves make absolute sense.
MOI, or Moment of Inertia, is essentially an object’s resistance to twisting. “For a putter, that translates to a rock steady swing path and an enlarged area of forgiveness off the face. So all you have to do is aim,” says Rife.
Many of the latest oversized super-stable head designs on tour boast a 5,000 MOI. The ER9-10K Extreme mallet that Evnroll unveiled to the golfing world at the 2018 PGA Merchandise Show takes that figure and doubles it, up to an incredible 10,000 MOI.
To achieve ultra-high MOI it requires a really big putter head that is usually a combination of ultra-light aluminium and stainless steel that is about three times heavier. The ER9 features a milled 6061 aluminium body with strategically located hollow cylinders running the length of the head from face to rear along the extreme heel and toe to receive sizeable steel weights. This design keeps the overall size down to manageable levels while still achieving an astonishing 10,000 MOI.
The head shape is essentially square with a wide central cavity framed by alignment lines along each side and a single line in the center. This shape allows for a full range of short to long rod weights to dial in swing weight based on shaft length, grip weights and counter weights. To help reduce the size visually, the ER9’s aluminium body is anodized in a dark grey satin finish.
Like all Evnroll putters, the ER9-10K features award-winning “Sweet Face” Technology, an innovative and unique mill pattern engineered to deliver uniform performance across the entire hitting area of the putter face for unprecedented accuracy and zero dispersion. However, because of the extreme stability created by the 10,000 MOI, the parabolic grooves have been dialled back to produce the same energy transfer and gearing effect for off-centre hits.
The ultra light aluminium body with long heavy steel weights running along the length of the heel and toe allows for 15% more head weight, yet the ER9 swings effortlessly along the swing plane and “feels” like a much lighter swing weight. Having the lighter feel with the heavy head weight delivers excellent distance control and deadly accuracy.
Even the grip on the ER9 features high MOI. Evnroll’s patent-pending Gravity Grip features a 70g, 10” steel rod that travels the full length of the deep V underside of the grip. This places 85% of the grip’s total weight in the fingers below the shaft, promoting a toe-up square face to the swing plane. Weighing in at 120g, the Gravity Grip also acts as a counter weight to the additional head weight, providing even more overall stability.
The ER9 will admittedly not appeal to all, especially traditionalists, but for those who absolutely, positively want to make every pressure putt, the ER9-10K will deliver.
“Having a putter that is so stable that it overrides nerves is often the key to success,” adds Rife. “The ER9-10K is stability on steroids!”
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