Because it is not as elastic, and snaps back faster due to its lower rate of deflection, and lower rate of movement, and therefore: faster recoil. Ie, kevlar, often rated above 600 and some at 900, snaps back faster, with less deflection, less power, higher frequency of vibration, creates more spin given an identical tension/etc.. Faster snap back, at mid range tensions, creates faster rpms. Shorter shots with less power and more spin on them given the same rate: applied power: tension:ra, etc. How long before they make a braided kevlar, half copoly, and edged? If the snap back is too fast, it does not grab the ball as much, say on high tensions. If it's too slow, on low tensions, it does not grab the ball as much either depending on typical player frame head speed. Hence Rafa's mid range: 55/52lbs, on rpm blast: 224 stiffness rating, edged string, high ra: original apd frame, not cortex, head heavy, small grip, giving him so much snap back. Kevlar strung at reference tension will feel way stiffer than any other string, and that is why so many stringers string it lower by 10%. Not just to lower elbow damagestiffer strings inject higher frequencies of vibration into elbows), but to lower stiff feel, and create more deflection, and more snap back.
I recently did an experiment, where I used a Mantis 295,
Mantis Pro 295 Tennis Racquet Specs:
Head Size: 98 sq. in. (632.26 cm)
Length: 27in (68.58cm)
Strung Weight: 10.8oz (306.17g)
Balance: 5 points Head Light
Swingweight: 302
Stiffness: 64
Beam Width: 21.5mm / 21.5mm / 21.5mm /
Power Level: Medium
String Pattern: 16 Mains & 19 Crosses
Read More http://www.tennisthis.com/tennis-rac...ro-295-review/
a very low powered frame. Strung it with gut at 60lbs. INjected silicone into the handle. Added lead to the entire hoop. Crosses were L-tec 4s, a teflon injected squoval shaped cross with very lubricated snap back and high cof. The first three crosses: Shortest at top: 55lbs. next down: 60lbs. Third down: 65lbs: fourth down: 45lbs. Fifth down: 45lbs. All the way down: back up to 65lbs. The effect was this: Serving power and accuracy increased to a high degree (hitting in the lower range area on cross), and yet, ground strokes were comparitively low/mid range in power, yet high in spin (16 x 19). I hit three aces in a row against a guy who just won an open tournament. ( 9 out of 10 first serves in, and some at ridiculously high pace and accuracy for my normal range.) INcreased twist/kick. Then the gut snapped at grommet shear.
I recently did an experiment, where I used a Mantis 295,
Mantis Pro 295 Tennis Racquet Specs:
Head Size: 98 sq. in. (632.26 cm)
Length: 27in (68.58cm)
Strung Weight: 10.8oz (306.17g)
Balance: 5 points Head Light
Swingweight: 302
Stiffness: 64
Beam Width: 21.5mm / 21.5mm / 21.5mm /
Power Level: Medium
String Pattern: 16 Mains & 19 Crosses
Read More http://www.tennisthis.com/tennis-rac...ro-295-review/
a very low powered frame. Strung it with gut at 60lbs. INjected silicone into the handle. Added lead to the entire hoop. Crosses were L-tec 4s, a teflon injected squoval shaped cross with very lubricated snap back and high cof. The first three crosses: Shortest at top: 55lbs. next down: 60lbs. Third down: 65lbs: fourth down: 45lbs. Fifth down: 45lbs. All the way down: back up to 65lbs. The effect was this: Serving power and accuracy increased to a high degree (hitting in the lower range area on cross), and yet, ground strokes were comparitively low/mid range in power, yet high in spin (16 x 19). I hit three aces in a row against a guy who just won an open tournament. ( 9 out of 10 first serves in, and some at ridiculously high pace and accuracy for my normal range.) INcreased twist/kick. Then the gut snapped at grommet shear.
Comment