This activity is about the lever as a basic tool. The ancient Egyptians used levers in building the pyramids. Although it is not known exactly how they erected the great obelisks, it's a pretty ...

so if it's a tool designed for a job then you needn't worry. The main aim of using a metal tyre lever is increased strength, but I'm yet to find a rim and tyre combo that the plastic Rim Stix can ...