Fabric roller blind, which comprises: - a support frame, intended to be fixed at an opening of a building; - a handle bar, slidably associated with said support frame, provided with an axial cavity and extended along an extension axis between a lower termination and an upper termination (5"); - at least two synchronization chains (6, 7), connected to said support frame, mechanically connected to each other, subjected to a tensioning force (Ft) and adapted to synchronize the advancement of the terminations (5', 5") of said handle bar during its movement, including: - a first synchronization chain, provided with a first internal end housed inside said handle bar and slidable within this; - a second synchronization chain, provided with a second internal end, mechanically connected to the first internal end of said first synchronization chain, housed inside said handle bar and slidable within this; - adjustment means, placed within said handle bar, comprising a first adjustment body, connected to said first synchronization chain and a second adjustment body, connected to said second synchronization chain and to said first adjustment body; the fabric roller blind is characterized in that said second adjustment body comprises at least one longitudinal guide, substantially parallel to said extension axis, and said first adjustment body is slidably free to be moved along said longitudinal guide and that at least one between said first adjustment body and said second adjustment body comprises at least one first pressure element, which is susceptible of exerting a friction force (Fa) between said first adjustment body and said second adjustment body, retaining said first adjustment body constrained in an operative position along said longitudinal guide, with tensioning forces (Ft) between said synchronization chains (6, 7) lower than said friction force (Fa). - a support frame, intended to be fixed at an opening of a building; - a handle bar, slidably associated with said support frame, provided with an axial cavity and extended along an extension axis between a lower termination and an upper termination (5"); - at least two synchronization chains (6, 7), connected to said support frame, mechanically connected to each other, subjected to a tensioning force (Ft) and adapted to synchronize the advancement of the terminations (5', 5") of said handle bar during its movement, including: - a first synchronization chain, provided with a first internal end housed inside said handle bar and slidable within this; - a second synchronization chain, provided with a second internal end, mechanically connected to the first internal end of said first synchronization chain, housed inside said handle bar and slidable within this; - a first synchronization chain, provided with a first internal end housed inside said handle bar and slidable within this; - a second synchronization chain, provided with a second internal end, mechanically connected to the first internal end of said first synchronization chain, housed inside said handle bar and slidable within this; - adjustment means, placed within said handle bar, comprising a first adjustment body, connected to said first synchronization chain and a second adjustment body, connected to said second synchronization chain and to said first adjustment body;