back in the early-mid '80s I worked as a tire changer for a chain of tire retailers. We had a mechanic who did all the front-end alignments and brake jobs etc, and he had an apprentice/helper who worked with him. When cars with drum brakes came in, they liked to each take a side and race to see who could get them done faster. I remember timing them once, and they both could remove and replace the shoes and the spring kits in less than 45 seconds.