[yazetaw]

Dear Kuma-san,

In response to your quesiton about shinai design, perhaps I misunderstood the meaning of your question; however, I as I understand it, "dobari" does not usually refer to the grip or 'tsuka' portion of a shinai, but rather, the 'ha' or blade portion, above the guard, or tsuba. A dobari-shinai is usually one with a large circumferance mid-section.

If you were refering to the tsuka, or grip portion of the shinai, some design aspects include circular and oval cross-section types. An oval cross-section grip, which resembles the tsuka of a real sword or bokuto is called a "koban" type tsuka.

Concerning dobari and standard (straight) shinai types, dobari are often said to be easy to swing, because a greater percentage of the weight is distributed lower down the body of the shinai, resulting in lower inertial loads at the "working end," as compared to a straight shinai of equal weight in which more weight is distributed towards the tip. The curving arc of the bottom of a dobari shinai is said to more closely approximate the curve of a Japanese sword. Advantage is a matter of personal perference; however, and even it the ranks of high ranking sensei we can see a range of both types in use. I prefer a heavy, straight shinai, with a lot of weight at the kensen, or tip.

As for tsuka design, by far the round cross-section type is most commonly used. For one thing, it is adequate for proper execution of techniques, and on the practical side, it allows more flexible re-use of individual slats as replacement parts for another shinai's repair. Some appeal of the koban, or eliptical cross-section tsuka is that it contributes to correct mochi-kata, or formation of proper grip method, and hasuji-tadashi, or correct angle and line of the blade while swinging and striking. We may infer though, that in the course of a normal approach to kendo study, and over the years, correct shinai mochi-kata and hasuji-tadashi can be mastered with a regular round type tsuka, as we can see in use by the overwhelmingly greater number of practitioners using this type. I have used both types, but prefer a large diameter, round tsuka, as it is more more comfortable after lots of practice, for consequtive days.

Perhaps beyond the scope or your quesiton, but please allow me to comment on tsuka length while we are on the subject. It is said that long tsuka are preferred by those who employ lots of oji-kaeshi waza, or techniques used in response to an opponents technique (these techniques usual require diagonal or lateral movements of the shinai.) While those who rely on tobi-komi waza, or long distance, jumping-in techniques, prefer short tsuka (as they require little off-axis movements, and the farthest possible 'reach.') I think these too are a matter of personal preference; however, I do believe that we should all be striving to develop a complete kendo in which we employ all techniques as apporpriate to the circumstances. As a general approach to determining the proper tsuka-gawa, or grip-covering, length, the end of the tsuka, or tsuka-gashira, is placed inside the bend of the right arm elbow. The position where the right hand naturally falls is considered by many the most biomechanically efficient location. A "chibi-debu" type, or short and fat, I use a quite short 3-7 tsuka-gawa, based on the determination method described.

I hope my viewpoints will be useful for your consideration. I invite your further comments or reaction.

M.I. Komoto
Chiba, Japan