A key source came out in 2017, based on a French survey.
Meixner, E. 2017. Etude d’évaluation sur les services vélos – Enquête sur les ateliers d’autoréparation de vélos. ADEME [ADEME did one just on bike workshops. This is a key source.] https://www.heureux-cyclage.org/IMG/pdf/cahier_ateliers_autoreparation-services_velos_ademe-2017.pdf
