| Rear suspension device for a bicycle, wherein said device comprises:(a) a first pivot (1) having a first axis of rotation, a second pivot (2) having a second axis of rotation, and a third pivot (3) having a third axis of rotation;(b) a first axial compression shock absorber (7);(c) a linkage unit (6);(d) a first sensor unit (5); and(e) a first magnet (10)wherein- said first axis of rotation, said second axis of rotation and said third axis of rotation are parallel;- said first axial compression shock absorber comprises a first end and a second end, wherein said first end is attached to said first pivot and said second end is attached to said second pivot; and- said linkage unit is attached to said second pivot and said third pivot and rotates about said second axis of rotation and said third axis of rotation;characterized in that- said first sensor unit is located on a surface of said linkage unit and comprises at least one Hall-effect sensor located in a plane perpendicular to the third axis of rotation, wherein each Hall-effect sensor is located at a distance d1 from said third axis of rotation;- said first magnet is:• a cylindrical or cylindrical shell magnet having an axis of rotational symmetry which is perpendicular to the parallel faces thereof; or• a prism-shaped magnet comprising two polygonal parallel faces and an axis of rotational symmetry which is perpendicular to said parallel faces;wherein the direction of the magnetic moment of said first magnet is perpendicular to said axis of rotational symmetry, wherein said first magnet is attached to said third pivot;wherein the third axis of rotation and the axis of rotational symmetry of said first magnet are aligned and wherein there is a distance d2 between said first sensor unit and said first magnet, and wherein:- d1 is between 0.1 mm and 50 mm; and- d2 is between 0.01 mm and 50 mm. |
