It remains the archilles heel of a mountain bike: the rear derailleur on the rear wheel. Due to its exposed position, it can get caught on obstacles or bend or even break in the event of a fall. If you touch an obstacle with the rear derailleur at full speed, the derailleur can slip into the rear wheel, damaging the gears and the rear wheel and even sending the whole bike into a knockout.

However, there is a way out: the rear derailleur protectors from Branchy or Parrier. These work like crash barriers that deflect the forces acting on the control center. These useful accessories can save the tour and prevent expensive repairs, but certainly won't win any beauty contests. These protectors also have an archilles heel: they are attached using cable ties, and the ones supplied look sturdy, but will presumably either slip or stop working in the event of a serious impact.