Lever a place to stand, and I shall move the Earth with it' is a remark of Archimedes who formally stated the correct mathematical principle of levers (quoted by Pappus of Alexandria). It is assumed that in ancient Egypt, constructors used the lever to move and uplift obelisks weighing more than 100 tons. A lever is a beam connected to ground by a hinge, or pivot, called a fulcrum. The ideal lever does not dissipate or store energy, which means there is no friction in the hinge or bending in the beam. In this case, the power into the lever equals
Shimano Total Integration lever applying tension to the gear cable, the smaller one incrementally releasing it. The Rapidfire mechanism was subsequently adapted to be used in STI levers. In 1990, Shimano introduced their STI shifting levers for road bicycles, which completely integrated the brake lever and shifter. It also redesigned the brake "hoods" where riders commonly rest their hands. This new design worked like a normal brake lever in the longtitudinal plane, but also allowed the rider to shift to a larger cog by pushing the lever so that it pivots laterally. Behind the brake lever, there is a smaller lever that shifts