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Racquet matching

Q: I can sort of understand matching two racquets, if one is lighter and has a lower swingweight, but I’m having trouble getting started on matching three racquets where the measurements seem to be all over the place. Any tips?

A: The first tip is to use our on-line tools so you don’t have to wade through mountains of calculations by hand. For example, you could use the Racquet Optimizer for fast and easy modeling of simple racquet modifications, but typically you would use the Racquet Customizer. (Each of these is available to USRSA members under the “Tools” heading at www.racquettech.com.)The second tip is to realize that it is not always possible to match two (or more) racquets. For example, there is no way to modify the flex of a racquet, so if you hope to end up with matched racquets, you must start with similar racquets that have the same flex. Even then, you may not be able to match the weight, balance, and swingweight, but at least the possibility exists. When it’s not possible to match the weight, balance, and swingweight of two racquets, Racquet Customizer will tell you which characteristics can be matched.The third tip is that adding mass under the grip at 10 cm up from the butt cap does not change the swingweight, even though it changes the weight and balance.The fourth tip is to use the Racquet Customizer solution that works best in your situation. Racquet Customizer will calculate a lot of different ways that two frames can be matched, but some of them will call for adding a lot of lead tape in inconvenient positions on the frame. As a rule of thumb, you want to keep sections of lead tape to 4 inches or shorter, so that the actual result will better correspond with the calculated goal. Because there are so many solutions, you can pick and choose based on what you want.The fifth tip is to re-measure after every modification, to ensure that your modifications are correct.Here is an example of three frames. The first is standard length, while the other two are 1/16-inch shorter. The first is the heaviest, while the other two weigh the same. The first and second have the same balance point, while the first and third have the same swingweight.

(Notice that we converted fractional inches to decimal centimeters for the Length measurement.)These measurements allow us to calculate how differently the racquets will respond in play:

Now we can start matching. Applying tip three, we add four grams of lead tape 10 centimeters up from the butt cap of frame 3. Measuring frame 3 after this modification reveals that adding this weight also moves the balance point to almost exactly where we want it. This gives us two racquets with the same weight, balance, and swingweight, and one racquet to which we can add weight to increase the swingweight.Use Racquet Customizer to calculate the amounts and positions where you will need to add mass to make the second frame (in our example) match the first frame. Racquet Customizer comes up with 98 solutions. Among these 98 solutions, you should find one that fits your needs.For example, the first 21 solutions require adding lead tape to the very tip of the racquet. If you don’t want to do this, you can eliminate all of these from consideration. The next 21 solutions require adding lead tape to the highly-curved section of the hoop, where precise placement is difficult. You might also want to discard any solutions that require tiny pieces of lead tape, or so much lead tape that there will be a huge lump at that location.In this case, we’ll go for solution 5, which does specify a short piece of lead tape at the tip of the racquet, but we can put it underneath the bumperguard to hide it from view. In the hoop, there will be four short sections of lead tape just over an inch long, and the remainder goes under the grip, just above where the player’s hand normally holds the racquet. Here are the masses and locations for adding weight to frame 2, so that it will match frame 1.

Here are the final measurements for our three matched frames:

The weight and swingweight are identical, and the balance is only .04 cm off. Calculating the center of percussion, recoilweight, and hittingweight (which can be calculated under the “tools” heading at RacquetTECH.com) shows that these racquets are indeed very well matched.Some racquets will be easier to match, and some more difficult, but using our on-line tools eliminates a lot of the drudgery, leaving you more time to consider how best to affect the modifications.

From the August 2005 issue
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