I've noticed most folks put lead at 9 and 3, but not 12-why?

[tomgavin]

Just curious as to why people aren't putting a little lead tape at the 12 o'clock position. Doesn't it balance out the stabilty issue and add a bit more "pop"? Thanks

[joe sch]

They want to improve the racket stability and minimize the head heavy additions. Adding lead at 12oc will just increase the hammer effect but not reduce twisting.

[Mark Carlisle]

On a 11.70 oz, 8 points head light frame, I added 3 x 3 gamma lead weights at 11, 12 and 1 o'clock and strung the frames down to 54 lbs - I was amazed at the extra pop it gave on grounstrokes as well as serves. Didn't notice any loss in stability

[Masamusou]

There isn't a loss in stability from adding weight at the top of the head, but one is able to ADD stability by placing weight at 3 and 9. I believe joe sch was saying that by placing weight at 12 that you increase the swingweight which will generally add power (assuming your swing doesn't slow down) but it does nothing to increase or decrease stability. Placing weight at 3 and 9 will increase the swingweight, not as quickly as 12, but it will increase torsional stability. Basically by adding weight at 3 and 9 you can get the added swingweight and extra pop, while also increasing torsional stability. Adding weight at 12 will only give you the added swingweight and pop, but has negligible, if any, effect on torsional stability (resistance to twisting).

[mary fierce]

A spinning ice skater with arms extended outwards spins faster as he/she pulls those arms in towards the body. We've all seen it, right? Similarly, weight added along the axis of rotation (e.g., at 12 o'clock) will increase the rate and/or tendency to spin (i.e., reduce stability)

[Masamusou]

I'm not sure it's quite the same thing. When the ice skater pulls their arms in, they completely take away the weight towards their outer reach, as well as air resistance. Air resistance is partly responsible for the slower spin rate with the ice skater, just as a parachuter that brings their arms and legs in will fall faster than one that is spread out. Air resistance acts over the surface area of an object, so by stretching out their arms, ice skaters increase their surface area, thus increasing the area that air resistance acts on. With a racquet, you are merely adding weight to the axis of rotation, you aren't taking away weight that is already towards the outside for torsional stability. That weight is still there, now if you take weight off of the 3 and 9 spots and add it to the 12 spot, then I would agree, but because there is a certain amount of weight out at 3 and 9 that isn't changing, I'm not sure the added static and swingweight will increase tendency to spin. I could be wrong, I'm just not exactly sure how you can reduce stability without reducing the mass that creates it in this case. I realize the overall weight and swingweight will increase by adding weight at 12, but you aren't taking weight away from 3 and 9 so I don't see how the stability is reduced.

[kreative]

more stable to add at 3/9 w/o increasing the swingweight too much. also doesn't raise up the sweetspot, and tortional stability. putting lead at 12 raises the sweetspot, and increases swingweight significantly w/ minimal addition of lead.

[perfmode]

I'm not sure it's quite the same thing. When the ice skater pulls their arms in, they completely take away the weight towards their outer reach, as well as air resistance. Air resistance is partly responsible for the slower spin rate with the ice skater, just as a parachuter that brings their arms and legs in will fall faster than one that is spread out. Air resistance acts over the surface area of an object, so by stretching out their arms, ice skaters increase their surface area, thus increasing the area that air resistance acts on. With a racquet, you are merely adding weight to the axis of rotation, you aren't taking away weight that is already towards the outside for torsional stability. That weight is still there, now if you take weight off of the 3 and 9 spots and add it to the 12 spot, then I would agree, but because there is a certain amount of weight out at 3 and 9 that isn't changing, I'm not sure the added static and swingweight will increase tendency to spin. I could be wrong, I'm just not exactly sure how you can reduce stability without reducing the mass that creates it in this case. I realize the overall weight and swingweight will increase by adding weight at 12, but you aren't taking weight away from 3 and 9 so I don't see how the stability is reduced.

Ice skaters don't tuck because of air resistance. They tuck because of the centripetal force. The farther out their arms are, the more force it will take to pull them around with the body. It will slow then down because the arms have to travel a greater distance. It is the same as the 1hbh. When you swing, you keep your forearm close to your body until you open up so that you get more headspeed.

[rich s]

adding weight at 12 o/c doesn't reduce torsional stability it just doesn't increase it as rapidly as putting it at 3 and 9 o/c.

this is the same EXACT principle as increasing swingweight only this time it is about the longitudinal axis rather than the axis of racquet rotation.

If you add mass at 12 o/c the mass is exactly on the logitudinal axis. as a result the increase in moment of inertia about the longitudinal axis is affected minutely. however by adding mass at the 3 and 9 o/c positions (the positions that are furthest from the longitudinal axis) you maximize the affect of the increase of moment of inertia about the longitudinal axis and the raquet is more stable torsionally. Just as with swingweight customization you cannot reduce torsional stability/moment of inertia about the longitudinal axis by adding mass.

wind resistance does not make the skater spin slower -- the increase in moment of inertia because he/she extends his/her arms outward is what makes the skater spin slower. conversely when the skater pulls his/her arms inward the moment of inertia decreases and the skater spins faster.

you cannot reduce moment of inertia by adding mass.

as a secondary affect to adding mass to the hoop to increase torsional stability you also increase swingweight because you are adding mass at a distance of over 20 inches from the racquet's axis of rotation. if you are considering adding mass at 12 o/c to increase the swingweight, consider adding mass to the 3 and 9 o/c positions instead. you will increase your swingweight and you will benefit from increased torsional stability.

[Masamusou]

So someone else provides an example that is incorrect in its principle and I get criticized for attempting to explain why it is incorrect? Well excuse me. We just got into moment of inertia in class yesterday. I'll admit, the air resistance thing is wrong, but I believe the basic principle that I tried explaining in my first response was still correct.

[perfmode]

So someone else provides an example that is incorrect in its principle and I get criticized for attempting to explain why it is incorrect? Well excuse me. We just got into moment of inertia in class yesterday. I'll admit, the air resistance thing is wrong, but I believe the basic principle that I tried explaining in my first response was still correct.

I was just correcting your air resistance theory. Air resistance has nothing to do with it. It's about centripetal force.

[rich s]

perfmode - it's about moment of inertia not centripetal force

[spinbalz]

It is about both moment of inertia and centripetal force, in the case of swinging a racquet they are related indeed.

Air resistance of course also counts for racquet maneuverability and counts very slightly for the spin rating of ice skaters, but it has no relation with the effects of adding lead tape.

[rich s]

All centripetal force plays into the equation is how tightly you have to grip the handle so the racquet doesn't fly out of your hand -- it doesn't play into torsional stability at all especially since torsional stability is measured about the racquet's longitiudinal axis and centripetal force is measured along/parallel the racquet's longitudinal axis.

[brian.sat]

I can only accept lead tapes on 6 O'clock only.

[D. Nelson]

......HIT him....!!!!!!!