In this test rig concept, the test pinion and test wheel are fixed on two parallel shafts connected with the slave gear with the same transmission ratio. The decisive advantage of this bracing principle is that only relatively small powers of the drive machine are required, even for high test powers.

So it is possible to carry out very efficient an reliable tests on the types of damage described and lubricant and efficiency tests on external and internal gears with a module of 3 to 12 mm. With the FZG back-to-back test rigs, investigations can be carried out on gears with center distances of up to 200 mm or a module of up to 12 mm. Small gear test rigs can be used to perform tests on gears with a module of 0.3 to 1 mm, which are used, for example, in the fields of microsystems, robotics, and medical technology. More than 50 FZG back-to-back test rigs for cylindrical gears of different types are operating at the FZG.