djokovic and his "flexible" frame

[corners]

The longitudinal stiffness of a racquet has very little influence on the power (speed) of shots hit in the center of the stringbed. (If you went to 100 stiffness that would be a different story, but the difference between RDC 50 and 70 isn't that great.) Stiffness does have an influence on power potential for off-center shots, but this is more about hoop stiffness - how well the hoop resists twisting distortion. Many modern racquets, with their relatively thick beams, can be quite stiff in the hoop but flexible longitudinally (what the RDC machine measures). I would guess that Novak's stick is pretty stiff around the hoop but flexible in the throat.

Also, the power potential of a racquet ("The percentage of impact speed returned by the bounce of the ball from the racquet.") is more important at low swing speeds. For us amateurs, the difference between a "powerful" frame and a "low-powered" frame can be pretty profound: 3-4 mph on our groundstrokes. But power potential becomes largely insignificant as swingspeed gets into the pro levels.

The pros are swinging frames around 360 swingweight, which means their power potentials are much higher than the sticks we use anyway, regardless of how stiff or flexible they are. The power potential of Djoker's stick is about 44% in the center of the stringbed. If he were to find a stick with 46% power potential (maybe a Big Bubba weighted to his specs) he would only gain about 1.5 mph on his forehand because he is swinging so fast (90mph or so).

This article explains how and why the "power" of a racquet becomes less important to shot speed as we swing faster: http://twu.tennis-warehouse.com/lear...ntribution.php

[Sreeram]

This thread makes no sense at all. Stiffer racquets are powerful with comparatively with less weight that is why all lighter beginners racquets are stiff. If u add weight to a racquet and increase it's sw then even If it is flexy it will still be powerful.
Players who play with stiffer frames are those who play with comparatively lighter frames. Eg rodick.

[LeeD]

Stiffer frames benefit the slow swinging player more than a fast swingspeed player.
When I hit with stiff big hoops, I get no more power than my Mfil200's. When I up the stiffness to 68, as in Aero500, I get no more power, usually less power.
When I used to borrow my buds Wilson2.6 grey stiffy, I hit softer shots constantly, with some going waaay long. He used my rackets, couldn't hit a penetrating ball if it landed beyond the baseline.
Slow swingspeeds get huge benefits from stiff rackets, and can't get softer flexing rackets to hit hard.
Fast swing speeds get little to no benefit from stiff rackets, but can make soft racket hit the ball with plenty of zip.

[Timbo's hopeless slice]

Originally Posted by BreakPoint

Personal preference. Same reason some pros use full poly strings and some do not, and some string at higher tensions and some string at lower tensions, and some use smaller racquets and some use bigger racquets, and some use heavier racquets and some use lighter racquets. It's just what you're accustomed to what your strokes and timing are grooved to.

^^^^^^^^^^

This, pretty much. All the pros have great techniuque, (well, DUH!), but the racquets they use just reflect what they happen to like. More often than not, this is whatever their first 'good' racquet was like when they were teenagers..

[kiteboard]

A strung up RA is lower by about 3 pts, than an unstrung RA. So his frame is really about a 54RA. But, he places lead lower, from the sixth cross down form the hoop, to about an inch below the bottom cross. His sw is about 371, and total mass: 360g. String is vs team gut main/alu power crosses: 60/58. The vs is a power string. The mass is lower on the frame with the lead. Sq. in is about 98. I play with a similar set up, and its got plenty of power with the pt57a not as flexy.

[Wilander]

Thx to kiteboard, corners and Kevo! Your answers make sense!
Probably the unstrung stiffness is about RA 54 and the lead near the throat increases the stiffness significantly. + I forgot he uses gut now, which gives additional power.

[Wilander]

edit: "dynamic stiffness"

[TennisD]

Originally Posted by ben123

i was kind of thinkin a bit the same like "how can he make such powerful shots with ra 50 and 60lbs strung"

Because stiffness/flex actually has relatively little to do with how much power you're getting on your strokes, or is at the very least quite low on a list of variables that includes weight, swingweight, swing TYPE, string, tension, timing, and so on. One could argue that for a guy like Djokovic a more flexible racquet would actually be beneficial due to the fact that he has an EXTREMELY long swing and a more flexible frame would allow him to more effectively pocket the ball/keep it in the stringbed longer than a stiffer frame might. Duh.

[kiteboard]

The string I use on the pt57A is vs team mains, nrg2 crosses. Mains are at 60lbs, first three crosses down are 52lbs, next 14 are at 58lbs, and last three are at 65lbs. Very good control/feel/touch. Mass at 360g.

[hoodjem]

Originally Posted by vsbabolat

His racquets are were
weight: 360g
Balance: 32cm
Swing weight: 371
http://hdtennis.com/grs/pro_racquet_...ibas_open.html

12.7 oz.

Is this weight strung or unstrung?

[Cup8489]

Originally Posted by hoodjem

12.7 oz.

Is this weight strung or unstrung?

String, I believe.

[Wilander]

Finally we learned that his strung racquet has an RA of 60 anyway.

[dr325i]

delete.......

[sureshs]

Originally Posted by Wilander

Finally we learned that his strung racquet has an RA of 60 anyway.

How did you learn it?

[niktub]

As simple as that.

[Wilander]

Originally Posted by sureshs

How did you learn it?

http://tt.tennis-warehouse.com/showthread.php?t=441393