In the case of early model pickers, chains are replaced and a sun gear grease modification is performed.

Gear greases consist of rosin oil, thickened with lime and mixed with mineral oil, with some percentage of water.

In San Francisco, where bicycle commuters often wear full-body spandex suits, my patient Carlos could easily be spotted: the Mexican man in mustard-colored work boots and painter’s overalls stained with gear grease, furiously pedaling an adolescent’s red Huffy.