Do your racquets mix or match?

You have at least 2 racquets, so that if your strings break, you have an identical frame to fall back on, right? That's what I was thinking for a good part of my tennis life. Until I started playing with racquets that looked the same, but felt very different. First, I thought it was misjudgment on my end, but then I started to realize that even a small difference in weight or balance had quite an impact on my game. I found myself marking my favorite out of 5 Wilson Hyper ProStaff 6.5s and playing with it all the time. And hoping that the strings wouldn't break :)

One of my best friends who loves both gear and data was kind enough to walk us through how we can uncover (or proof!) whether our frames are different. So without further ado, here's the first guest post for forehand.TV:

Us amateurs don't have easy access to racquet technicians that the pros do, and often times have to deal with poor racquet-to-racquet consistency for frames we buy off the shelf. Regentville tennis has a couple accounts with this problem with Wilsons in this post and this post.

As someone who loves the sports gear more than the sport, and incredibly picky about getting precise specs, I was quite worried when purchasing new frames that although they are the same make and model, their specs would be quite off. I was finally upgrading from the legendary Prince Original Graphite, a racquet that I've been using for 15 years, to the Babolat Pure Drive Roddick. However, would Babolat's quality control pass my test, given that they have a much shorter history of making racquets compared to Wilson and Prince?

Obviously, going by just "feel" of the racquet is not good enough for me, I need data. So I devised a few tricks that the amateur can use to spec their racquets.

Weight:

This is the easiest, just get yourself a digital scale that measures to fractions of a gram. Then, strip everything off your racquet (grip, grommets, etc) so that it is as bare as possible. In my case, I was very surprised to find the racquets were within 1.3 grams of each - very nice!

From Gear

Balance:

There are a few ways to do this. A cool trick I learned on the Regentville blog is to slide the racquets onto a stiff rod of some sort, and just see how they hang relative to each other. You can also do this with a pen in a store, just to guestimate which racquets may be close in balance before buying them.

From Gear

It is just the camera angle which makes it look off, the difference in balance was not perceptible using this method.

A slightly more precise method is to use a ruler and a flat level table surface, with a sharp edge. Hook the ruler or tape measure to the edge, and place the butt end of the racquet at a mark. Slowly push the racquet further off the table until it just barely begins to tilt on its own.

From Gear

Take a few measurements. Once I've gotten close to the balance point, I'll move the racquet in 1/16" increments and let go, dialing it in to the point where that small change will either cause the racquet to start tipping, or to stay on the table.

From Gear

Repeat with the other racquet to find its balance point. Try to keep everything identical, and to keep the racquet, table edge, tape measure, etc on straight lines or right angles to each other.

It's important to note both of these measurement techniques are relative. They require the racquets to be compared to be the same model. While I can get a measurement of "12.5 inches" using the latter technique, it means nothing comparing it to, say, my Prince Graphite. Even if I were to compare a Pure Drive to a Pure Drive Roddick, the comparison would not be valid.

I must have gotten lucky, as using these methods of approximation, my racquets showed the same balance. Only difference was one racquet seem to start tilting a bit faster, but the point which that occurred was the same.

The adjustment I had to make was very simple. I put 1.3 grams of lead tape at the butt end of the light racquet.

From Gear

That is only about 0.5% of the total weight (even less once I add grommets, grips, and strings) and has minimal effect on the balance and almost no effect on swing weight (when placed at the butt end) of the racquet. For comparison, the piece of rubber many manufacturers use to finish the top of a grip weighs 1.5 to 2 grams.

Swing weight?

Well, this is one thing I could not assess to a confidence interval that meant anything, so I didn't try. However, I'm lucky to live in NYC, home to RPNY, a shop that does a lot of customization for touring pros. They were nice enough to measure my racquets when they were brand new (never strung, plastic still on grip, original grommets). Specs below:

Racquet #1: Weight - 317.3 grams, Balance - 315 mm, Swing weight - 297 kg cm², Stiffness - 72
Racquet #2: Weight - 316.9 grams, Balance - 314 mm, Swing weight - 297 kg cm², Stiffness: 72

(FYI - stated spec for Pure Drive Roddick's is 315 grams and balance at 315 mm. The plastic wrap on the grip is about 2 grams. These frames were dead on spec)

Wow, that's pretty damn good! The difference in the delta of the racquet weights with my measurements and RPNY's can be attributed to variances in the grip, plastic wrap, and/or the grommets differences between the two racquets.

Color me impressed, and very lucky. I basically have two identical racquets. Am I skilled enough to require this precision, no. Am I happy, yes.

Out of curiosity, I additionally weighed two extra Pure Drive Roddicks in the store, and they came out to 319.0 and 315.9 grams. While I didn't measure balance (which is harder to correct at home than weight), I'm still very impressed with Babolat's consistency and quality control based on this little sample.

No comments:

Post a Comment