A bicycle chainring for engagement with a drive chain provided with rollers, the chainring comprising: a plurality of teeth (2, 3) extending from the periphery of the chainring, the roots of the plurality of teeth (2, 3) being disposed adjacent to the periphery of the chainring, the plurality of teeth (2, 3) including a plurality of narrow teeth and a plurality of wide teeth, the narrow and wide teeth (2, 3) being arranged in an alternating manner, each of the teeth (2, 3) having a front flank and a rear flank with respect to a drive direction of the chainring, wherein the front flank and the rear flank of two adjacent teeth (2, 3) define an U-shaped space when seen in the axial direction of the chainring for accommodating a roller of the drive chain, wherein each tooth (2, 3) includes a first chamfer in the front flank and a second chamfer in the rear flank, the first chamfer starting from the top of a respective tooth (2, 3), wherein both the first chamfer and the second chamfer extend on respective planes which are perpendicular to the plane of the chainring, wherein the first chamfer has a larger extension than the second chamfer, when viewed in the axial direction of the chainring, such that the U-shaped space, when viewed in the axial direction of the chainring, is steeper at the rear flank than at the front flank, characterised in that wherein the first chamfer is followed by a steep section (13"), the steep section (13") being steeper than the first chamfer when seen in the axial direction of the chainring, the steep section (13") extending up to a further section of the front flank which is responsible for the transmission of the force from the roller. a plurality of teeth (2, 3) extending from the periphery of the chainring, the roots of the plurality of teeth (2, 3) being disposed adjacent to the periphery of the chainring, the plurality of teeth (2, 3) including a plurality of narrow teeth and a plurality of wide teeth, the narrow and wide teeth (2, 3) being arranged in an alternating manner, each of the teeth (2, 3) having a front flank and a rear flank with respect to a drive direction of the chainring, wherein the front flank and the rear flank of two adjacent teeth (2, 3) define an U-shaped space when seen in the axial direction of the chainring for accommodating a roller of the drive chain, wherein each tooth (2, 3) includes a first chamfer in the front flank and a second chamfer in the rear flank, the first chamfer starting from the top of a respective tooth (2, 3), wherein both the first chamfer and the second chamfer extend on respective planes which are perpendicular to the plane of the chainring, wherein the first chamfer has a larger extension than the second chamfer, when viewed in the axial direction of the chainring, such that the U-shaped space, when viewed in the axial direction of the chainring, is steeper at the rear flank than at the front flank, characterised in that wherein the first chamfer is followed by a steep section (13"), the steep section (13") being steeper than the first chamfer when seen in the axial direction of the chainring, the steep section (13") extending up to a further section of the front flank which is responsible for the transmission of the force from the roller.