Aprendizagem colaborativa de condução de bicicleta
A group of friends meets regularly to volunteer their time helping anyone who wants to learn to ride a bike. They see cycling as an effective means of transport for a freer, more sustainable planet, and learners and instructors are welcome to get involved via the form.

Image: from the event entry at Agenda Porto.
Source: Agenda Porto (Câmara Municipal do Porto). Details can change; the original entry is the reference.