Grippy High-RPM Spin - No Snapback Required!

Discussion in 'Strings' started by travlerajm, Jun 25, 2013.

  1. Steve Huff

    Steve Huff Legend

    Joined:
    Feb 11, 2004
    Messages:
    7,276
    I'm not really surprised. I tried Gamma Extremem Spin a while back (a thin kevlar with a synthetic cross), and it had a lot of spin.
     
    #51
  2. ricardo

    ricardo Professional

    Joined:
    May 12, 2009
    Messages:
    828
    Interesting observation.

    However, I read in some TW University articles that a hybrid setup (60lbs mains/30lbs crosses) generated much less spin than another hybrid setup ((60lbs mains/60lbs crosses).

    Here's the link to that article (look at figure 10).
    http://twu.tennis-warehouse.com/learning_center/spinandstiffness.php
     
    #52
  3. travlerajm

    travlerajm Hall of Fame

    Joined:
    Mar 14, 2006
    Messages:
    4,416
    The mains in the 16x10 pattern have higher resistance to normal deflection, but no better stiffness to lateral deflection when strung @ 60/60 vs 60/30.
    A stringed needs to be stiff enough to compress the ball, because ball compression is the source of the overspin that leads to extreme spin when the strings are free to ride with the overspinning surface of the ball rather than resisting the overspin with friction
     
    #53
  4. ricardo

    ricardo Professional

    Joined:
    May 12, 2009
    Messages:
    828
    How much does technique account for spin generation?

    Does technique (Rafa Nadal technique) account for 50% of spin generation and the other half accounted for by equipment (frame/string)?

    IMO, technique accounts for 90% of spin generation while equipment accounts for a miniscule 10%. If this is the case, is it not better to spend your time to practice hitting like Rafa?
     
    #54
  5. travlerajm

    travlerajm Hall of Fame

    Joined:
    Mar 14, 2006
    Messages:
    4,416
    I would say it's more like 80/20.

    More importantly, it would take me 10,000 hrs of practicing the Rafa fh to feel comfortable using it. But it only takes an hr to change my strings.

    Which is the more efficient way?
     
    #55
  6. ricardo

    ricardo Professional

    Joined:
    May 12, 2009
    Messages:
    828
    Ball compression VS ball pocketing...

    Intuitively I understand that ball compression and ball pocketing are similar in the sense that more area of the ball are grabbed by the string helping to generate additional spin during the low-to-high swing of the racket face.

    During ball compression, more area of the ball are grabbed by the string because the ball is flattened out during impact on the stiff string.
    During ball pocketing, more area of the ball are grabbed by the string because the string pockets the uncompressed ball during impact on the less stiff string.

    Question:
    In your experience, which is more efficient in helping generate more spin, ball compression or ball pocketing?
     
    #56
  7. travlerajm

    travlerajm Hall of Fame

    Joined:
    Mar 14, 2006
    Messages:
    4,416
    Your intuition has some incorrect assumptions.

    Ball compression by itself does not increase spin unless the string bed has some freedom to move laterally.

    Ball pocketing in the normal direction ( perpendicular to bed) actually reduces spin unless the string bed also free to pocket in the lateral direction because more normal deflection means less ball compression.

    Ball compression reduces the radius of the ball. As the ball decompresses, its radius grows, and its rotational moment of inertia causes its surface to move faster than the racquet. If the string bed has no freedom for lateral motion, then the overspin is countered by friction, negating the effect of the compression.

    So a racquet that allows high lateral freedom but is very stiff in the normal direction will give good spin.

    In some cases, it is possible that the strings can actually assist in generating overspin by stretching laterally as the ball compresses. Then returning the energy as the ball decompresses.

    Technically, it's not the main/cross stiffness ratio that matters, it's the normal/lateral stiffness ratio that counts for spin.

    High normal stiffness is also important for another reason. It prevents denting. String bed denting reduces spin potential by directing the force vector less tangentially.
     
    Last edited: Jun 28, 2013
    #57
  8. travlerajm

    travlerajm Hall of Fame

    Joined:
    Mar 14, 2006
    Messages:
    4,416
    Weighted up the diablo to my spec range (curiously, it turned out to be 365 SW stock, so it didn't take much lead). Took it out for a hit.

    Hitting forehands was a pleasure. Definitely fits into the extreme spin category. My regular forehand drive seems to dip rapidly down into the court with extra margin. The feel is unique - feels nothing like the crisp kevlar/zx. Feels nothing like the kevlar/nylon strung conventionally (because it grips rather than pockets). Feels nothing like poly (because the grip is more secure at all impact angles). It's a new animal.

    I was hitting against a player with a beautiful heavyspin semiwestern forehand, and volleys still felt fine. This is the first time I've played with a setup this naturally spinny that was still easy to control at net, as it doesn't have that high a launch angle.

    I didn't get my serve dialed in because the racquet felt heavier than I was used to, despite my efforts to match SW close to my Blade. But when I did get the kinetic chain aligned right, it exploded nicely high up into the fence. So can't blame the stringbed.

    I'm going to have to try this on some other frames.
     
    Last edited: Jun 29, 2013
    #58
  9. newyorkstadium

    newyorkstadium Semi-Pro

    Joined:
    Jan 12, 2012
    Messages:
    585
    Just to confirm, the difference between this and a conventional kevlar/nylon setup is gauge and tension? Also, nylon strings can vary wildly in stiffness. If this is about main/cross stiffness ratio, wouldn't a natural gut or zyex cross be best?
     
    Last edited: Jun 29, 2013
    #59
  10. travlerajm

    travlerajm Hall of Fame

    Joined:
    Mar 14, 2006
    Messages:
    4,416
    Hit a few yesterday. The extreme spin was not quite as extreme anymore, and the stringbed was starting to play more like a conventional kevlar/nylon setup. I think it's because the kevlar loses more tension during its break-in period than the nylon, so the stiffness differential beteween mains and crosses is no longer so pronounced. I may try a larger tension differential next time.

    I think the key to getting the unique extreme spin with this type of setup is that the normal stiffness of the bed must be much higher than the lateral stiffness in the 3-to-9 direction.

    Factors that improve this ratio:
    1. Stiffer material in the mains than crosses.
    2. Pre-stretching the main.
    3. High tension differential between mains and crosses.
    4. Thicker gauge crosses (to increase the amplitude of the weave of the crosses, thereby decreasing lateral stringbed stiffness).
    5. Thicker gauge mains? (same logic as #4, but haven't tested this yet, as the lower stress on thicker mains might have an offsetting effect).
    6. Denser mains (again, to increase amplitude of weave of crosses).

    After stringing, the mains should have minimal weave angle, and the crosses should have maximum weave angle.
     
    #60
  11. travlerajm

    travlerajm Hall of Fame

    Joined:
    Mar 14, 2006
    Messages:
    4,416
    Another observation. The strings have started to permanently lock now. No more interstring sliding. This seems to be the biggest reason that the extreme spin is no longer so extreme.

    For the first hour or two, the spin is significantly more than with the spinnest shaped poly's. But after the strings start to lock, it's still quite spinny, but not amazingly so like it was for the first couple of hours.

    Next experiment: I'd like to try a large tension differential on a kevlar/ZX hybrid, to see if I can capture the dual benefits of normal/lateral stiffness ratio and interstring sliding, but in a setup where the sliding will be preserved a lot longer.
     
    #61

Share This Page