As an alternative to conventional steel bars for concrete reinforcement, glass fibre-reinforced polymer (GFRP) rebars offer a promising option for a durable, safe and low-maintenance reinforcement solution. Its advantages lie in its lower thermal conductivity combined with higher tensile strength and corrosion resistance. In contrast to steel rebars, it is still a challenge to find bond-slip models that accurately describe the bond behaviour of GFRP rebars with different surface and material properties. This is mainly because comercialized GFRP bars differ significantly from each other, namely due to the type of production. This results in dissimilar types of fibre-matrix combinations and distinct surface treatment characteristics, which in turn leads to different mechanical and bond properties. For this reason, the bond-slip models that are well established for steel reinforcement cannot be simply transferred to GFRP reinforcement without thorough adaptation, especially taking into account the large variety of existing GFRP bar typologies. This paper focuses on the study of the bond behaviour of helically wrapped GFRP rebars with loosely wrapped fibres that rest on the core with minimal indentation. Results from experimental pull-out tests are presented, demonstrating a distinctive mechanism for transferring bond forces from the reinforcement to the concrete matrix. Tested parameters include variations in the rebar diameter and the concrete strength class. The helical wrapping of the GFRP bar leads to a two-stage bond failure. The experimental results are compared with the analytical mBPE model and discussed.