How much does a tsuba affect the balance?

[piryohae3]

For example would a heavy shakudo tsuba change the balance point a lot more than one made of iron? Does a tsuba's weight really matter? How much of a difference does it make?

[raynor]

It does affect balance but not to a detrimental effect in the hands of someone with skill unless you go out of your way to put the biggest katana tsuba you can find on for example a wakizashi. More so then say a European saber, katanas had the point of balance further away from the grip. It's one of the reasons why they were such great cutters together with the thicker blade vs a slimmer spring tempered European Sabre, the slicing motion with the extra niku in the appleseed shape left you in real trouble if cut.

[Northman]

Agree with Raynor here.

 

Tsuba definitely affects the balance of a sword, particularly the point of balance by adding or subtracting weight closer to the kashira. That said, weight and distal taper of the blade (difference between moto kassane and saki kassane, and moto haba and saki haba respectively) play the biggest role in balance. Size of the nakago also affects the point of balance, and of course sori can effect the overall balance and handling of a sword significantly.

[Ken-Hawaii]

As a long-time sword swinger, it's easy to feel the difference in balance between tsuba, & I've changed out several of them over the years.

[Guest]

From a practical viewpoint, as Ken says, a huge difference.

 

I suggest at least 1000 suburi (swinging cuts to a focused point) before considering making any change, as the concerns may not lie in the actual weight or balance of the weapon, but rather the perception of those two.

 

[PNSSHOGUN]

The Yamada family outlined using particularly heavy Tsuba during Tameshi would greatly increase cutting power on a body.

[ROKUJURO]

The dimensions of a sword blade, and then especially the length of NAKAGO and TSUKA, will probably influence the balance more that the TSUBA. 

[mas4t0]

It's purely physical.

 

Find the point of balance of the sword (including the tsuka). This is the Centre of Mass (CoM), the CoM is the point at which a force may be applied to cause a linear acceleration without an angular acceleration.

 

The distance from the tsuba to the CoM along with the mass (and distribution thereof) of the sword and the mass of the tsuba itself will determine how the CoM will move in response to the tsuba.

 

A mass of 100g added at 50mm from the current CoM will have the same effect as 50g at 100mm, as the moment is the same.

 

Due to the tsuba being relatively close to the CoM, it would have nowhere near as much of an effect as adding mass to the kashira (which is why western swords use pommels).

 

If you want to understand this fully, search for "Centre of Mass."

 

I think though that the effect may be missed somewhat if we only consider the CoM.

 

As Malcolm expressed, the results are best felt and assessed during suburi where you're getting feedback on the dynamics of the sword.

 

Dynamics are also purely physical, so can be easily calculated, but it's best done with software rather than pen and paper as it gets somewhat more involved to calculate.

 

The effect of the tsuba will be small but noticeable. If you search from "Weapons Dynamics Computer" in Google you'll find a well put together tool. You can adjust different parts and see how it affects the overall dynamics of the sword.