As bikes navigate city streets after dark, they are often equipped with lights. The lights make the bikes visible to cars or other bikers, and the hazards of traffic less dangerous.
Imagine that as solitary bikes come together, their lights begin to pulsate at the same cadence. The bikers may not know each other, or may only be passing each other briefly, but for the moments they are together, their lights synchronize. The effect is a visually united presence, as groups of bikes illuminate themselves with a gently pulsing, collective light source.