A telescopic seat post for a bicycle frame has a tubular telescopic element for supporting a seat. The telescopic element is mounted so as to be slidable along a longitudinal axis of a seat tube of the bicycle frame. A tubular supporting element is mounted so as to be slidable within the telescopic element, the supporting element has a fastening section that can be connected to the seat tube by a fastener which can be inserted transversely to the longitudinal axis of the seat tube.