# Lead tape at handle bottom vs along handle

#### pico

##### Professional
When putting lead tape at the handle, does it matter if it is put around the handle at the bottom vs along the handle straight on?

#### One Handed Dynasty

##### Semi-Pro
I’ve always like to put lead/silicone in the bottom of the handle near the level of the butcap since you get the most effect with the least weight. Then you can add a small bit of lead to the top to account for minor differences between racquets. I like a more polarized feel though.

#### Dartagnan64

##### G.O.A.T.
I recently put lead tape in strips along the handle with a Shock shield grip. Bumped up the handle weight so my racket went from 4 points HL to 8 points HL.

Putting weight at the bottom of the handle will increase static weight without much effect on Swing weight since it's below the fulcrum. I was looking to modestly increase SW so I didn't want all my weight right at the bottom.

#### Irvin

##### Talk Tennis Guru
SW is RW plus the product of weight and balance. SW = RW + (m*r^2.) The farther from the COM you place weight the greater the change in balance. The more you spread the weight out on the longitudinal axis the greater the inertia (RW & SW.)

#### Firepandas

##### Rookie
SW is RW plus the product of weight and balance. SW = RW + (m*r^2.) The farther from the COM you place weight the greater the change in balance. The more you spread the weight out on the longitudinal axis the greater the inertia (RW & SW.)
Is it the "product" of weight and balance, or the "sum"? And is there actually a way to calculate it from weight and balance? I thought SW had more nuance to it.

#### Irvin

##### Talk Tennis Guru
Is it the "product" of weight and balance, or the "sum"? And is there actually a way to calculate it from weight and balance? I thought SW had more nuance to it.
SW is the inertia of a racket from the 10 cm axis that passes through the Center of Mass (COM.). Inertia is the inertia of a physical object at the COM aka RW. You can use the parallel axis theorem to calculate the inertia of a physical object anywhere on a parallel axis that passes through the COM. SW is technically termed a secondary moment of inertia (SMOI) and RW (MOI) is the physical racket’s moment of inertia.

SMOI = MOI + m*r^2 or better said SW = RW + m*r^2 where r is the distance between the SMOI axis and COM.

Assume you have a racket with a RW of 165, balance of 32 cm, and weight of .325 kg. Your SW would be:

SW = 165 + (.345*(32-10)*(32-10) = 331 kgcm^2

#### Irvin

##### Talk Tennis Guru
is there actually a way to calculate it from weight and balance
Yes, you can use a torsional pendulum to determine the racket‘s inertia, MOI, or RW (whatever you want to call it. From there you can use the parallel axis theorem to determine the SW.

##### Professional
hmmm, so tail weighting, at the trap door specifically, will only have an impact on balance and static weight,
but it will NOT have an impact on swing weight, plow/stability?

#### Firepandas

##### Rookie
hmmm, so tail weighting, at the trap door specifically, will only have an impact on balance and static weight,
but it will NOT have an impact on swing weight, plow/stability?
Correct. You can't lower swing weight by adding weight. You can only lower it by removing weight. In regards to plow/stability, a higher static weight should provide you with that

EDIT: I misread what you said kinda. Adding any weight will add to swing weight, where you put it on the racquet determines how much it adds to it though. Adding weight at the top of the hoop will increase SW more than adding it to the base of the handle. So by adding weight at the handle, you are increasing swing weight, but it might not be by much.

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##### Professional
In regards to plow/stability, a higher static weight should provide you with that
this is what I was looking for, thank you for your input!
cheers

#### Purestriker

##### Professional
When putting lead tape at the handle, does it matter if it is put around the handle at the bottom vs along the handle straight on?
Unstrung customs has photos of their process and they usually have it around the handle at the very top. They also use the wider strips of lead for the handle.

#### Irvin

##### Talk Tennis Guru
hmmm, so tail weighting, at the trap door specifically, will only have an impact on balance and static weight,
but it will NOT have an impact on swing weight, plow/stability?
That is NOT CORRECT. Inertia is additive just like weight the more you add the more you have. If your racket weighs 325 g and you add 5 g you end up with 330 g.

If you add 5 g of mass at 10 cm from the SW axis (butt of racket) you add 0.5 points to the SW. As a matter of fact if you add 5 g at 10 cm above the SW axis the SW change is the same as at the butt (I = mr^2) it does not matter if you add weight above or below the 10 cm axis. If you add 5 g of weight at the 10 cm SW axis you will have no change In SW. The longer along the handle you spread the weight (centered on the 10 cm axis) the greater the change.