Politecnico di Torino - Corso Duca degli Abruzzi, 24 - 10129 Torino, ITALY

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BicyclesEffort reductionGear ratioSpeed changesport


The present invention relates to a derailleur for speed changes of bicycles and any other type of muscle-powered velocipede. The proposed solution offers numerous advantages in terms of greater speed of command and execution of the change of speed, reduction of physical effort and increase in the number of speed ratios, thanks to a mechanical system integrated with springs and in relation with the chain and the driving wheel.

Technical features

The current technologies used for every type of bicycle (or velocipede) driven by the muscular strength of the driver and / or passengers, by means of a mechanical system for the transmission of power to the driving wheel, are different for road or for mountain use (high number of combinations of gear ratios) and for racing uses (better gearbox maneuverability). The current technical problems have so far limited the number of sprockets and consequently the number of gear change ratios. The proposed solution allows a quicker, more comfortable and less forceful change of speed, thanks to its innovative derailleur support system for the gearbox with two rotating elements. They operate in a concordant manner on the derailleur itself, exerting an arcuate conical force and providing sliding guides to accompany and facilitate the movement of the chain from one sprocket to the other.

Possible Applications

  • It can be installed on all types of velocipedes, regardless of whether by road or mountain or run;
  • This technology overcomes the problem of the limited number of speed changes currently available on the market;
  • The invention is susceptible of numerous modifications and variations falling under this technology.


  • Rapidity, comfort and reduction of the force required for gear changes;
  • Reduced space for gear changing action (shifting);
  • Reduction of the misalignments of the chain from the sprockets, with an increase in the speed safety of the velocipede;
  • Reduction of the overall weight of the bicycle while increasing the number of rear sprockets.