In addition, the material of bamboo was changed to the one which had different characteristics (closer to presently used carbon fiber) by adding heat or other processes, and the composition of Chokyu became complicated.
そして竹材も熱を加える事などで、同じ竹でも物性の違う材料（現在の炭素繊維やカーボンファイバーに近いもの）を生み出し、構造も複雑になっていった。