Tennis Industry magazine


Racquet Tech

By Bob Patterson

Building Up Handles, Tracking Match Stats

More than a decade ago, heat-shrink sleeves revolutionized the way we built up a racquet handle. The method was so easy and precise, other methods soon disappeared. While the new Siz-Up from Lorow may not make heat-shrink sleeves obsolete, they do offer some distinct advantages.

Siz-Up ( comes in four sizes: +1, +2, +3 and +4, which increase the handle size by 1, 2, 3 or 4 sizes, respectively. For example, using a +3 Siz-Up on a 4-1/8” handle will result in a 4-1/2” handle.

With heat sleeves, each layer causes the handle to become less defined as the edges of the bevels get more rounded. Also, each sleeve adds about 15 to 20 grams, depending on the length of the handle, so if you are going up two or three sizes you will significantly alter the weight and balance of the racquet.

The Siz-Up still adds weight, but it is less than heat sleeves and much less if going up multiple sizes. The full-length +1 Siz-Up adds 10.2 grams; +2 adds 14.2 grams; +3 adds 20.3; and +4 adds 25.2. (Added weight is less if the length is trimmed.)

Siz-Up is easy to install — just trim to match the handle length, place on a clean handle and secure with a new grip. Each unit adapts to the shape and flare of the butt cap. We tried several sizes on different handle shapes and had no slippage or movement. However, a piece of double-sided tape on the face bevel of the handle holds Siz-Up in place and makes installing the grip easier. (One important thing to note is that with Siz-Up, more rectangular-shaped handles will morph into more square-shaped handles.)

The Siz-Up works great, and we encountered no problems. We even added a +4 to a 4-5/8” handle, resulting in a 5-1/8” handle that was perfectly shaped and felt great. It added 25 grams to the weight of the racquet and changed the balance 13 mm more head light, but it didn’t change the swing weight enough to register. (If we had used heat sleeves, it would have added a total of about 88 grams.)

Coming: ‘Smart’ Connection for Any Frame

Anyone who’s seen professional tennis on television has seen the amazing match statistics gathered during a match. Soon, that information will be available for your players’ next club or league matches. At least two companies are launching products that allow players to track their stats.

Zepp tennis ( has a device that attaches to the butt cap of any racquet (top photo)and captures, measures and analyzes your swing in three dimensions and records 1,000 data points per second. (We are currently playtesting the Zepp and will provide a full report later.)

The second device (above) is from Shot-Stats ( and attaches to the racquet’s strings much like a vibration dampener. The device in fact weighs about as much as two dampeners and features a high-resolution, high-contrast screen allowing you to view many of your metrics immediately. The company is just wrapping up a Kickstarter fund-raising campaign and hopes to have the device on the market before the end of the year. (We will provide a playtest as soon as the device is available.)

Both devices use Bluetooth connections to send data to Apple or Android devices. (Note: A new ITF rule for 2014 allows data collection during a match, but that data can’t be used during the match, because it would be considered “coaching.”)

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About the Author

Bob Patterson , the founder of the RacquetMAXX customization service, is a Master Racquet Technician with more than 20 years of experience. He was RSI's Stringer of the Year in 2005. He is Executive Director for the U.S. Racquet Stringers Association.



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