The whole thing started in a basement. In 1996, a corner of the Santropol Roulant where delivery bikes went to rest their wheels slowly became, thanks to one determined volunteer, a full community bike shop. The premise hasn't changed: show up with a flat tire or a mystery rattle, leave knowing how to fix it yourself. Volunteer mechanics guide rather than do, which makes Santrovélo less a repair shop than a standing weeknight classroom with grease on the workbench. Three evenings a week, pay-what-you-can, no one turned away. For most of what Montreal's potholes can dish out, they've got a wrench and someone to show you how to use it.