Wilson K Factor KSix-One Tour 90 Racquets

Length 27 inches 69 centimeters
Head Size 90 square inches 581 square centimeters
Weight 12.5 ounces 354 grams
Balance Point 12.375 inches
31 centimeters 9pts Head Light
Construction 18 mm Straight Beam
Composition nCoded High Modulus Graphite / Carbon Black
String Pattern 16 Mains / 19 Crosses
Flex Rating 67 Range: 0-100
Swing Weight 336 Range: 200-400


Subtle revisions in design, when added together and taken as a whole, can often result in big changes in performance. Roger Federer's new racquet, the Wilson KSix-One Tour 90 is a case in point.

While at first glance it may look like the changes from nCode to KFactor may have happened in the material build up, a close inspection of the KSix-One Tour 90 reveals some other subtle design updates to the racquet, as well.

The new KSix-One Tour 90 takes a page from the Wilson ProStaff Original 6.0 85, the racquet that wrote the book on classic racquet performance. Take a close look at the new handle of the KSix-One Tour 90 and you'll notice a shorter pallet with more of the graphite shaft exposed below the yoke - just as with the ProStaff Original 6.0 racquets.

Although we're not aware of any physical advantages to the ProStaff 6.0 85 like handle pallet, we do know it will silence critics that noticed this difference between the version of the Tour 90s used by Roger Federer and those available to the rest of us.

Another subtle update to the KSix-One Tour 90 is the string spacing in the sweetspot of the racquet. Members of our Talk Tennis message boards were quick to point out that Federer's version of previous Tour 90s had only four cross strings along the PWS bar at 3 & 9 o'clock on the racquet face. The retail versions of the Pro Staff Six-One Tour 90 and the nCode nSix-One Tour 90 both had five cross stings through this area. With the new KSix-One Tour 90 we now get four cross strings, just like Federer.

After taking a close look at the racquet we had to ask, can blending design hints from the ProStaff 6.0 85 with a technology as new and mysterious as KFactor (Wilson still hasn't told us what KFactor is) result in a better Tour 90? And, most importantly, can this blending of old and new enable us to hit the ball like Federer?

To answer these questions (and to take advantage of some terrific California Central Coast weather) we hit the courts for a three-week playtest.