The cyclist stopping to help has interrupted a rhythm that effort will have to rebuild.

Stopping costs more than the minutes it takes. Momentum, breathing, the settled rhythm of a long ride all have to be built again from cold, and whoever stopped pays that afterwards, out of sight of the person they helped. Kindness often carries a hidden second cost paid later. That is worth knowing both when you receive it and when you are deciding whether to offer it.

If somebody helps you, understand they may be paying further down the road, and say more than a quick thanks. If you stop for someone, allow yourself the slower finish.