F was totally intrigued by what I claimed to be significant differences in playability between stringing machines. He wanted the truth and suggested a "Myth Busters" experiment at his expense.
The plan was simple. He owns several matched rackets. He will get one strung by someone with an electronic machine and one on my dropweight.
To prevent any string biasness, he bought three packets of the same synthetic gut from the commercial stringer. One was used to string his racket electronically.
The second pack was given to me to string his other racket at the same tension and same stringing pattern (ie. 2 piece with exact tie-off holes)
After measuring the tension (by frequencies) of both stringbeds, we proceeded to hit some balls at the tennis court. Three of F's tennis partners (about ntrp 5.0 players) joined us and played with the unmarked rackets. Each had exactly 5 minutes. Only F and me knew the differences. The others were kept totally in the dark.
Unanimously, all expressed a strong preference for the dropweight strung racket. The three friends even thought the electronically strung racket had dead, old and stale strings!!!
The differences all of us felt most significant were:
1. stringbed liveliness,
2. power, and
3. spin
String tension was measured after every 30 minutes of play for 2 hours. After the session, the strings were cut out, preserving several long continuous pieces intact from the same spot in both rackets. Specifically, the centre 6 mains and between crosses 6-12.
Elasticity of the four lengths of strings were tested by holding them under tension at 50 lbs in the dropweight.
Here's our findings:
Initial String Tension
- The electronically strung racket registered a frequency about 58hz higher, translating to about 6 lbs tighter.
After Play String Tension
- At 30, 60, 90 and 120 minutes of continuous play, the dropweight strung racket (orange line) lost much less tension than the other racket (blue line). The rate of tension loss also stabilized after about an hour whereas the electronically strung continued losing tension even at 120 minutes of play.
Elasticity Test
- Both pieces from the electronically strung racket lost a lot more elasticity.
- Both dropweight strung pieces of string stretched about 2.3% more than the other string.
- The full stretch was recovered when tension was released for all the strings.
As far as F and his partners are concerned, they have found their answers.
Note:
Since this test could affect someone's livelihood, no details nor pictures were posted. Neither would any questions concerning the racket, string brand or electronic machine be answered.
Well... Six pounds less (from any machine) will result in a big difference in 1. stringbed liveliness, 2. power, and 3. spin.
ReplyDeleteDo any of your differences as noted above come from the type of stringer, of just different tension?
Both were strung at 55 lbs. Everything was held constant between the two rackets. Even the time when both rackets were strung was monitored.
ReplyDelete"F" was told the electronic machine had been calibrated only that morning.
well, again, there are a lot of other variables between stringers than just the reference tension, even if it is calibrated. Your dropweight uses flying clamps, etc.
ReplyDeleteTry this: with your machine, string two racquets - one normally and one six pounds tighter. I'll bet your blind testers will notice the difference.
Yes, you are right. Even with a tension difference of only 2 or 3 lbs, most players can already feel a significant difference.
ReplyDeleteWe were aware of this from the start since we measured the frequencies before hitting.
To us, what stood out was the differences in tension loss and string elasticity after play. Would a 6 lbs difference cause this extra string deterioration?
Perhaps we should repeat this test? With the electronic machine string at a lower tension by 6 lbs or the dropweight higher?
To each his own?