This invention relates to a method of controlling the operation of a winder in which method while forming at least one fiber web roll the fiber web is brought on the web roll via a nip formed by a first support drum and the web roll, which first support drum is driven by a first drive assembly (20) applying controllable torque to the drum and the winding force is applied to the web roll by a second drive assembly (22). In the method the second drive assembly (22) is controlled based on the indicative speed difference of the second drive assembly (22) and setting a friction coefficient for determination of maximum winding force.