The invention relates to a water-based ink composition comprising a latex containing styrene-butadiene rubber particles, and a coloring agent, the glass transition temperature of the styrene-butadiene rubber particles being 0\xb0 C. The invention is characterized by a torque threshold determination element which provides a torque threshold value that depends on the torque gradient and lies below the desired torque value. The inertial valve does not open in response to rider-induced forces.