Phil Mickelson has used a blade-style, heel-shafted putter for years. (Kinnaird/Getty Images)

In this week's U.S. Open edition of the Equipment Report Mailbag, PGATOUR.COM Equipment Insider Jonathan Wall discusses Phil Mickelson's Odyssey Versa putter, players switching to TaylorMade's R1 Black at the U.S. Open and KBS's C-Taper shaft. 

Have a question about the latest golf equipment or what the pros are playing? Send a tweet to @jonathanrwall.

Credit: Getty Images

By Jonathan Wall, PGATOUR.COM Equipment Insider

Lee Westwood likely won't win his first major championship this week after posting 7-over 77 on Friday. But when it comes to equipment, there's no question the Englishman wins the award for having the most unique item in the U.S. Open field.

In search of a tip stiff driver shaft that could produce a flatter ball flight at Merion, Westwood swapped out the Aldila Tour ATX 65 3.0TX in his PING G25 driver — 11.5 degrees instead of his standard 10.5 degrees — and went with a prototype Aldila Rogue shaft.

Shaft manufacturers have experimented with different materials over the years in an effort to change, among other things, kick point, torque and ball flight. While there are plenty of high quality shafts on the market, Aldila's Rogue could be the most advanced.

According to John Oldenburg, Aldila's Vice President Engineering/Product Development, the shaft uses a very expensive, extremely stiff petroleum based carbon fiber that is typically used for aerospace applications — like satellites, where extreme stiffness and ultra-lightweight materials are required. 

The material used to design the shaft is nearly twice as stiff as any material Aldila has used in the past. The tensile modulus (stiffness) is 125 million pounds per square inch (msi); typical carbon fibers historically used in shafts have ranged from 33 msi to 65 msi. 

"In terms most people can understand, the material is four times stiffer than steel but less than a third of the weight," Oldenburg said. "The Rogue shaft is built on our ultra-successful new “TOUR” platform (same tooling and technology as the Tour Green and Tour Blue).  By incorporating this new material we are able to make the shaft stiffer and lower torque without adding weight."

By placing the material in the top third of the shaft, Aldila was able to slightly counterbalance the shaft to work with heavier driver heads and the longer length of today's drivers.  

The low torque and increased stiffness of Rogue makes it the preferred shaft for players with high swing speeds looking to control launch angle and reduce spin — something Westwood wanted when he made the switch.

The company only made 24 Rogue shafts and brought them all out for the first time to the U.S. Open. The shafts were serialized (1 through 24) with a laser engraved number on the shaft. Westwood was the first player to put the shaft in play and received the shaft marked “1 of 24”.

At the moment, the shaft is a TOUR-only model, but Oldenburg said if there's sufficient demand for Rogue, there could be a limited commercial run. The price tag for one of these shafts would likely be around $1,000 each.

Rory McIlroy says he will hit driver around seven times on Merion's short layout.

By Jonathan Wall, PGATOUR.COM Equipment Insider

ARDMORE, Pa. — Firm and fast. It's a term oft-used to describe U.S. Open courses in the past, but following several days of torrential downpours at Merion Golf Club that delayed play on numerous occasions Monday and nearly put the par-4 11th under water, the mindset of every player in the field changed.

"It's a real shame that we've had so much rain," Luke Donald said on Tuesday. "I think that most people would really like to see this course play firm and fast. And I don't think we're going to get that this week. But it's a good challenge, this course. I think if it was firm and fast this course, even despite the length, would hold up just as well as any other U.S. Open course."

At just under 7,000 yards (6,996 yards, to be exact), Merion is the shortest course in major championship history since Shinnecock Hills Golf Club (6,996 yards) hosted the U.S. Open in 2004. While length and lightning-fast green may not be an issue this week, players will have to contend with a number of other hurdles — namely the potential for mud balls in the narrow fairway, the course's diabolical rough and three lengthy par-3s over 230-plus yards.

"I've been saying this is the longest short course I've ever played," Steve Stricker said. "Everybody's told me how short it is and I've been wearing out 3-irons and utilities into some of these holes. So it's fairly long and it's still going to be very difficult."

Given the current conditions at Merion, players have been working with a number of different clubs in preparation for Thursday's first round. Here's a look at what they could have in the bag.

Driver, fairway woods and hybrids: Forget about getting a couple extra yards of rollout on tee shots; players will have to worry about mud balls more than anything else off the tee, which likely means you want see many players going with extra loft to keep the ball in the air, or less loft to get additional roll.

Of course, that's assuming the driver even makes it out of the bag. Luke Donald, one of the shorter hitters on the PGA TOUR, said he only hit five drivers during a recent practice round.

"I think there's only a couple of holes I probably only hit five drivers out there this week," Donald said. "Looking at the course, 5, 6 and 18, holes where I'd like to get a little bit of roll after my tee shots, because they're very long and I'm going to have long shots in. I'm going to lose that roll."

As far as fairway woods go, they could be the go-to club for a number of players in the field like Phil Mickelson, who went back to using his Callaway X Hot 3Deep fairway wood off the tee in Memphis in preparation for the U.S. Open. Mickelson can work the club in both directions and was averaging over 300 yards last week, two things that could come in handy at soggy Merion.

On the flip side, there's always the chance you could see players be a little more aggressive and go with just a driver or long iron like 2011 U.S. Open winner Rory McIlroy.

"I imagine I'll hit seven drivers out here," McIlroy said. "So I'll still play quite aggressively off the tee. But it's funny, there's seven drivers and then there's a lot of irons. So it's sort of there's not really many where you're hitting a 3 wood or 5 wood, it's sort of like driver or iron and that's sort of weighing how most guys will approach it this week."

And then there's the group considering higher lofted fairway woods and hybrids. Bubba Watson and Hunter Mahan tested PING G25 7-woods on Tuesday as an option for shots out of the thick rough — the wider sole helps get the ball out the rough — and to fill a specific yardage gap.

Irons: When it comes to irons, you won't see many players tinker with the setup the week of a major. You will, however, see some consider different long iron options as an alternative to the standard fairway wood or hybrid.

Rory McIlroy goes between a Nike VR Pro Combo 2-iron and 19-degree Nike VR_S Covert, depending on the course conditions. McIlroy confirmed he'll likely stick with the 2-iron this week, but he was going to make a final decision following his practice round on Tuesday.

Jason Day could use his TaylorMade RocketBladez 1-iron with a 125-gram UST Mamiya Recoil Proto shaft, or go back to his go-to long iron — a TaylorMade Tour Preferred MC 2-iron.

Other players might opt to go with a driving iron at Merion. Titleist's 712U or Adam's DHy have more forgiveness than the traditional long iron with a similar ball flight.

There's also a select group that could pull their long irons for easier to hit options like Cleveland's 588MT. Keegan Bradley is currently using a 588MT 4-iron — he said it goes the distance of a standard 3-iron — instead of a carrying a 588TC 3-iron. He was also testing a 588MT 2-iron in the run-up to the U.S. Open to potentially use as a "bullet" iron off the tee.

Wedges: Fresh grooves have become almost become a prerequisite at the U.S. Open — when the greens are playing firm and fast. Dustin Johnson picked up a new set of face plates for his TaylorMade TP xFT wedges, and Sergio Garcia added new TaylorMade ATV wedges (50, 58 degrees) with fresh grooves. Holding the green is crucial at the second major of the year.

However, with soft conditions around the greens, players could opt to pass on extra bite and add more bounce to their wedges or go with a different grind that has wider sole and a prominent trailing edge that prevents digging.

Putter: Depending on the weather between now and Thursday morning, Merion's greens could be rolling slower than usual. The USGA went out to the 14th green on Tuesday and confirmed it was rolling 12.4 on the Stimpmeter.

While that's not exactly slow by TOUR standards, Tiger Woods hinted players are already adding lead tape to the putter head to help them adjust to the the slower-than-usual greens.

"The mindset coming into a U.S. Open is they're going to be hard and fast and crusty," Woods said. "But that's obviously not going to materialize this week with this weather. Some of the guys are already throwing lead [tape] on their putters, and getting a little more weight behind it to try and adjust."

Photo credit: @GregSabellaCG

By Jonathan Wall, PGATOUR.COM Equipment Insider

To commemorate the 2013 U.S. Open at Merion Golf Club, Odyssey is releasing a USA-themed Versa #7 putter, limited to 250 pieces. The limited-edition version performs the same as the standard white-black-white Versa #7, however, Odyssey decided to make this one unique by adding a blue line to the bottom and white White Hot insert.

The insert and line on the standard white-black-white model are usually black. Each putter is individually stamped on the sole and comes with a custom Odyssey USA putter cover.

The putter measures 35 inches and has a head weight of 343 grams. It carries a suggested retail price of $249 (right-hand only).

The Versa #7 has been a popular model this season. Rickie Fowler switched to the putter at the Arnold Palmer Invitational presented by Mastercard and still has it in the bag; Dustin Johnson, Jim Furyk, Phil Mickelson Ernie Els and Freddie Jacobson have also worked with the #7 at some point in the past few months.

Boo Weekley is one of three players this year to win with graphite shafts in his irons. (Halleran/Getty Images)

By Jonathan Wall, PGATOUR.COM Equipment Insider

Eleven years have passed since Rich Beem made equipment history at the 2002 PGA Championship, becoming the first and only player to claim one of golf's four major championships with a set of composite shafts (Aldila's Tour Gold) in his irons and wedges.

Beem didn't know it at the time, but his victory would end up being a rare one-off for composite iron shafts, also known as graphite shafts, on golf's biggest stage.

Over the past decade, graphite has become the material of choice on the PGA TOUR for shafts in drivers, fairway woods and hybrids, as pros have shifted away from steel and into lighter composites that increased swing speed and distance.

The same, however, can't be said for composite shafts in irons and wedges, which never really gained a following. Steel is still king on the PGA TOUR when it comes to iron shafts, but over the last few months, composite iron shafts have made some noise, with three players using them to win four PGA TOUR titles.

There's no question composite shafts have come a long way in the last several years. Gone are the questions about consistency and feel that kept many players from trying the shafts out in the first place. Today's shafts are not only better, they also come in a wide variety of weights and flexes that give pros numerous options.

The recent improvements have clearly worked, because a number of the top players in the world have started using composite shafts in their irons over the last few years — including Matt Kuchar and Boo Weekely, who both recorded victories with composite-shafted irons in the last few weeks.

Kuchar's been a composite trend-setter, using Aerotech's SteelFiber i95 Constant Weight shaft since 2008 — Brandt Snedeker also plays the same 95-gram SteelFiber shaft — to vault to fourth in the Official World Golf Rankings following his win at the Memorial Tournament presented by Nationwide Insurance.

Ranging in weight from 74 to 125 grams, Aerotech Golf's SteelFiber is a composite shaft with a unique twist. Unlike traditional composites shafts that are made up of graphite fibers and expoy resin, SteelFiber has a graphite core that's surrounded by an outer layer of steel fiber that eliminates distortion of the shaft during the swing.

"The early graphite iron shafts were made with inferior materials, processing and designs" said Aerotech Golf's president Chris Hilleary. "They started to gain traction at one point, but all of those pitfalls basically created a retreat of the use, and steel continued to dominate from there. That's when all of the shaft manufacturers started to concentrate on driver and fairway wood shafts. I saw this huge void in the market and started out to design a composite iron shaft that stronger players could embrace."

By adding steel fibers to the shaft, Aerotech was able to increase the weight of with 1/5 of the materials used in graphite, while also maintaining the playability and consistency of low torque steel.

Hilleary also noted the vibration dampening characteristics of the graphite core reduces the risk of injury and player fatigue during the round.

While the shaft won't be available until later this summer, Aldila's RIP graphite is made a big statement at the Crowne Plaza Invitational at Colonial when Boo Weekley used a set in his Cleveland 588 MB irons to hit 75 percent of his greens in regulation and claim his first PGA TOUR win since 2008.

"Boo used our 115-gram RIP shaft in his irons and if you saw they way he hit the ball that week, he had what may have been the best ball-striking week of the season," said John Oldenburg, Aldila's vice president of engineering and product development. "The big knock on graphite has been that it's inconsistent and you can't control the ball. Well all that's out the window now. We're at the point now where we don't feel like we're trying to catch up to steel; we feel we've surpassed steel."

The low-torque iron shaft, which will also be available in a 90-gram version, features a patented straightening technology that makes it two times structurally straighter than steel.

"Torque is very important in irons when you're trying to control the ball," said Oldenburg. "With this shaft you're also getting more true loft and lie than you would in any steel product."

With 18 weight, flex and torque combinations, UST's Recoil is another composite shaft making waves this season. Tim Clark recently switched to the shaft and finished T-7 at the Crowne Plaza Invitational at Colonial. Jason Day also went with a UST Mamiya Recoil Proto (125-gram) in his TaylorMade RocketBladez Tour 1-iron at the HP Byron Nelson Championship and liked it so much, he had UST build him an entire set of RocketBladez Tour irons with Recoil shafts to test out at home.

"One of the drawbacks about graphite shafts in the past have been — especially when you get into the heavier weights — has been trying to duplicate feel," said Robb Schikner, UST Mamiya's vice president of sales and marketing. "When you get into those heavy weights that are closer to what you see in steel, the shaft gets really stiff around the hoop direction and doesn't ovalize."

Whereas a steel shaft would give and ovalize a bit during the swing, graphite iron shafts of the past had walls that were so thick, it decreased ovaling and the energy transfer within the shaft.

UST's Recoil shaft was designed with denser graphite fibers that allowed the R&D team to decrease the wall thickness. With 19 different, denser layers within the shaft, the company was able to create a design that, while lighter than most steel shafts, can be bumped all the way up to 125 grams for pros that prefer a weightier version.

Not only that, UST was able to use the Recoil design to create a shaft that, according to Schikner, was more "steel-like." Players were able to flight the ball like they could with their steel shafts and get trajectory control on everything from full shots to knockdowns and three-quarter swings.

The new design has UST bullish about the future, so much so that Schikner believes graphite could go from being the exception to the norm in iron sets on TOUR in the next 10 years.

"I think 10 years from now graphite [iron shafts] are going to be the norm," Schikner said. "You'll see graphite iron shafts out on TOUR on a consistent basis, rather than the exception that it's been."

TaylorMade's black R1 driver will hit stores on June 10. (Courtesy of TaylorMade Golf)

By Jonathan Wall, PGATOUR.COM Equipment Insider

When an all-black TaylorMade R1 driver first showed up on the USGA's Conforming Driver List at the end of April, TaylorMade officials were quick to squash the rumors surrounding the mystery club.

What was known at the time was that driver was a smaller-headed 400 cc, left-handed R1 prototype that, according to TaylorMade Public Relations Manager Dave Cordero, wasn't coming to retail.

While the 400 cc prototype fell short of making it to retail, TaylorMade announced on Thursday that an all-black 460 cc R1 model would debut next week on the PGA TOUR at the FedEx St. Jude Classic in Memphis, before hitting retail shelves on June 10.

The new model will also mark the first time since 2010 that the company has produced a driver with a black crown.

“For three years we have only made white drivers and have heard from a number of golfers who just prefer the look of black,” said President and CEO, Mark King. “Our commitment has always been to provide golfers with the best performing golf equipment. The R1 Black gives players who prefer that color access to our industry leading technology.”

Like the white R1, the all-black version will have the same adjustability features -- 12 loft-sleeve settings, 7 face-angle position, and two moveable shot-shape weights -- as well as an ultra-light Aldila RIP Phenom shaft.

“Members of our tour staff now have two color options,” King said. “We will see a number of them opt for R1 Black, while others will stay in the white version to take advantage of the white/black contrast and alignment benefits.”

The new driver will be available on June 10 with a retail price of $399.

Nike's Rob Burbick describes the equipment that Tiger Woods uses on the PGA TOUR.

Jason Day might carry a 1-iron to Muirfield this summer. (Ehrmann/Getty Images)

By Jonathan Wall, PGATOUR.COM Equipment Insider

IRVING, Texas -- Traditional long irons have become obsolete in recent years with the introduction of easier-to-hit hybrids and utility irons. At the 2013 Masters, only two players in the field carried a traditional 2-iron -- one of them being third-place finisher Jason Day, who used a TaylorMade Tour Preferred MC 2-iron during the week. 

Even though the iron is course-dependent -- Day switches between a 14.5-degree TaylorMade RBZ Stage 2 fairway wood and the Tour Preferred MC 2-iron depending on the layout -- it's clear the Aussie has some old-school tendencies when it comes to his equipment. 

It seems fitting that Day, the HP Byron Nelson Championship winner in 2010, would turn back the clock at the tournament that honors legendary golfer Byron Nelson and put a TaylorMade RocketBladez Tour 1-iron in the bag. 

Looking for a particular setup for the British Open at Muirfield, Day and TaylorMade Tour reps discussed a number of potential ideas about a month ago, including taking out the Day's driver and putting in a 2-wood. 

When they couldn't get the right configuration with the shaft and ball flight, Day kicked around the idea of going with a 1-iron to achieve the ball flight he was looking for off the tee. 

TaylorMade never produced a 1-iron in the RocketBladez line, so reps decided to do the next best thing, bending a 2-iron to 16.5 degrees and making the shaft a 1/2-inch longer. Day also went with a UST Mamiya Recoil Proto (125-gram) graphite shaft instead the current True Temper Rifle Flighted 6.5 shafts in his irons.

Day tested the club on Tuesday and liked it enough to pull his 2-iron and put the new iron in play.

"I was out there today and hit a couple of -- it was downwind and it was a 10 to 20 mph wind out there -- and there was a couple that went 300 [yards] easy with the bounce and roll as well. I want to say today with the wind hit about four, maybe five drives total [during the Pro-Am]. Everything else was a 1-iron and I didn't pull out the 4-wood at all. The ball flight was very strong."

While TPC Four Seasons will never be confused with a links-style layout, Day said he felt the course was the perfect place to test out the club ahead of the British Open -- especially with wind gusts expected to be anywhere from 15-20 mph the rest of the week.

"What the experiment was, was we were going to try a 1-iron and try it out here because we know if we have a 1-iron here and it works well in the wind, we go overseas to the British this year with full confidence that it's doing to go the right distance and can come out low and hit different types of shots when I need to. I know that it's not the British Open course but the wind is very strong here."

Outside of this week's HP Byron Nelson Championship -- Day said he used the 1-iron off the tee on nine holes during Wednesday's Pro-Am -- it's unclear when he'll use it again. 

With the Memorial Tournament and U.S. Open coming up, he hinted it could get some additional work before the British Open in July. 

"I think that it would be a very good club [at Merion, site of the U.S. Open], but I don't know until I get there. I'm definitely going to use it this week and I'm not too sure what I'm going to do with it for Memorial, but I know I'm going to use it at the British."

By Jonathan Wall, Equipment Insider

IRVING, Texas — Despite having only posted posted only one sub-70 round in competition since he switched to TaylorMade's Ghost Spider S belly putter, Padraig Harrington said he has no plans to go back to a conventional-length model anytime soon.

Harrington changed putters at the Wells Fargo Championship and opened with an 8-over 80 in the first round and promptly missed the cut. He followed the rough week up with a T75 at THE PLAYERS.

"I had no three-putts last week," Harrington said. "In my own stats, I only missed two putts under 8 feet which would be an all-time record, so it's still in the bag. And that was on tough greens last week. I would be happy if I putted like that all the time."

Looking for a something that would improve his putting stats -- he's currently ranked 123rd (-.123) on the PGA TOUR in Strokes Gained-Putting and 131st in putts made from inside five feet -- Harrington decided to give the belly putter a try.

“The R&A and USGA support the rules of golf and (anchoring) is well within the rules,” Harrington said at the Wells Fargo Championship. “I think (anchoring) is bad for the game of golf. But if something’s going to help me for the next three and a half years, I’m going to use it."

Like most putters, Harrington said the belly model has taken some getting used to -- especially on tap-in putts.

"I nearly dropped [the putter] on the ball at one stage last week because I'm not used to handling the putter and things like that. You're still not quite sure when you go to tap in a putt even from 18 inches when you're leaning in you just go and do it normally or as a belly putter, the familiarity is an issue."

Fans will have a chance to buy a rare Ashworth shirt honoring Fred Couples. (Photo: Ashworth Golf)

By Jonathan Wall, PGATOUR.COM Equipment Insider

To commemorate Fred Couples' induction into the World Golf Hall of Fame on May 6, Ashworth will release 300 individually numbered Fred Couples edition shirts.

Each shirt in the collection will be numbered inside the placket, with Couples receiving the first shirt (1/300). According to Ashworth, the color of blue (azure) is Couples' favorite and features double-knit EZ-TEC2 performance fabric.

“When you think of Ashworth, you immediately think style and of course Fred Couples,” said Susan Bush, VP of Ashworth. “We are very excited for Fred to be inducted into the World Golf Hall of Fame and are extremely honored to create a special shirt that truly reflects his personality and favorite elements.”

The shirt also features Couples' signature in green on the inside neck and green thread on the top button of the placket in honor of his 1992 Masters victory.