虫むしゴム

noun

valve rubber; inner tube valve rubber

Refers to the small rubber piece inside a bicycle or car tire valve that prevents air from leaking. Common in bicycle maintenance contexts.

• 自じ転てん車しゃの虫むしゴムが劣れっ化かして空くう気きが漏もれていた。

  The valve rubber on my bicycle had deteriorated and was leaking air.