This half-automatic gear simplifies biking. Instead of controlling on the one hand the front and on the other hand the rear derailleurs separately; this gear controls both components synchronically. The driver doesn’t need to change his pedal rhythm. Gearing is done almost without noise and very reliable. Because bikes are usually exposed to most different weather conditions; also the requirements to corrosionresistance of the bearings are high. For this reason, the designers of the innovative gearing decided among other things to use the robust iglidur® plain bearings from igus®.