The invention relates to a method of threading a fibrous web (W) onto a circular cylindrical object (3, 19) in a reel-up (2) for a paper-making machine (1). The reel-up (2) comprises an endless flexible belt (6) mounted for rotation along a predetermined path of travel. The endless flexible belt (6) is positioned adjacent the circular cylindrical object (3, 19) during winding and the fibrous web (W) residing on the outside surface (8) to engage the circular cylindrical object (3, 19) during winding such that the endless flexible belt (6) is deflected from the predetermined path of travel. When a fibrous web (W) is to be threaded onto the circular cylindrical object (3, 19), the circular cylindrical object (3, 19) is placed at a distance from the endless flexible belt (6) such that the endless flexible belt (6) is no longer deflected from the its path of travel. A narrow tail (17) is cut from a fibrous web (W) that is to be threaded and the narrow tail (17) is advanced on the outside surface (8) of the endless flexible belt (6). The circular cylindrical object (3, 19) is moved towards the endless flexible belt (6) such that the circular cylindrical object (3, 19) comes into contact with the narrow tail (17) and an adhesive substance is applied to the to the narrow tail (17) such that the narrow tail (17) will adhere to the circular cylindrical object and starts to be wound on the circular cylindrical object (3, 19), whereafter the narrow tail (17) is widened. The invention also relates to a reel-up (2) capable of carrying out the method.