System (1) for assisting in driving a bicycle (100) by sending a haptic feedback to a cyclist, comprising: - means for detecting the current value of a target quantity (q, v); - a memory module (7) wherein an optimal profile of said target quantity is stored or storable, as a function of a spatial position (x) of the bicycle along a predetermined path or as a function of time (t), configured for supplying an optimal value of the target quantity (qmax; vmax) corresponding to the current spatial position (x) of the bicycle along the predetermined path or corresponding to the current instant (t); - a comparator module (8) configured for determining a quantity representative of the error (eq; ev) between said current value of the target quantity (q, v) and said optimal value of the target quantity (qmax; vmax) supplied by the memory module (7); - an actuator (4) applicable to a portion of the bicycle (100), suitable for generating vibrations; - a control module (5) configured for determining a vibration frequency (f) of the actuator (4) based on said error (eq; ev) between the current (q, v) and the optimal values (qmax; vmax) of the target quantity and for generating a command signal of the actuator (4) so that the actuator vibrates at said vibration frequency (f), wherein said vibration implements the haptic feedback to the cyclist.