Handlebar group for bicycles, comprising: - a handlebar, comprising a central section, for fixing to a handlebar stem, and two lateral gripping sections; - a handlebar stem comprising in turn: - a front head, comprising first fixing means configured for locking said handlebar; - a rear collar, comprising second fixing means configured for fixing to a tube of a fork; - a central extension, for connection between said front head and said rear collar; characterized in that said first fixing means of the handlebar comprise: - a front tubular body shaped to accommodate said central section of said handlebar, said front tubular body comprising a front part shaped to surround a front face of said central section, and a rear part shaped to couple with a first end of a tightening rod, - and a front portion of said central extension, shaped to rest on a rear face of said central section of said handlebar; said central section of said handlebar being locked between said front part of said front tubular body and said front portion of said central extension; said second fixing means comprising: - a rear tubular body shaped to accommodate an end section of a tube of a fork, said rear tubular body comprising a rear part shaped to surround a rear face of said end section of a tube of a fork, and a front part shaped to couple with a second end of said tightening rod, - and a rear portion of said central extension, shaped to rest on a front face of said end section of said tube; said tightening rod being positioned to longitudinally cross said central extension, and being configured to connect said front tubular body and said rear tubular body. - a handlebar, comprising a central section, for fixing to a handlebar stem, and two lateral gripping sections; - a handlebar stem comprising in turn: - a front head, comprising first fixing means configured for locking said handlebar; - a rear collar, comprising second fixing means configured for fixing to a tube of a fork; - a central extension, for connection between said front head and said rear collar; - a front head, comprising first fixing means configured for locking said handlebar; - a rear collar, comprising second fixing means configured for fixing to a tube of a fork; - a central extension, for connection between said front head and said rear collar; - a front tubular body shaped to accommodate said central section of said handlebar, said front tubular body comprising a front part shaped to surround a front face of said central section, and a rear part shaped to couple with a first end of a tightening rod, - and a front portion of said central extension, shaped to rest on a rear face of said central section of said handlebar; said central section of said handlebar being locked between said front part of said front tubular body and said front portion of said central extension; said second fixing means comprising: - a rear tubular body shaped to accommodate an end section of a tube of a fork, said rear tubular body comprising a rear part shaped to surround a rear face of said end section of a tube of a fork, and a front part shaped to couple with a second end of said tightening rod, - and a rear portion of said central extension, shaped to rest on a front face of said end section of said tube; - a rear tubular body shaped to accommodate an end section of a tube of a fork, said rear tubular body comprising a rear part shaped to surround a rear face of said end section of a tube of a fork, and a front part shaped to couple with a second end of said tightening rod, - and a rear portion of said central extension, shaped to rest on a front face of said end section of said tube; said tightening rod being positioned to longitudinally cross said central extension, and being configured to connect said front tubular body and said rear tubular body.