A tread for a pneumatic tire in which air column resonance sound is reduced and wear of the groove fences and tread portion are caused to be approximately the same, while drainage performance is maintained, wherein a plurality of groove fences are formed and are installed within at least one circumferential groove, extending from the bottom of the circumferential groove, and block at least 70% of the cross-sectional area of the circumferential groove, and the bending parameter of the groove fences, defined as E.Math.I/(h3l) (where E is the modulus at 10% elongation of the material used for the groove fences, I is the second moment of area of the groove fence, h is the height of the groove fence, and l is the width of the groove fence) is at least equal to 250 Pa and at most equal to 350 Pa.

A heavy duty tire comprises a tread portion provided with annular land zones divided by circumferentially extending main grooves. At least one of the land zones is provided with first recesses disposed at one edge of the first land zone, second recesses disposed at the other edge of the first land zone, sipes extending from the first recesses to the second recesses, and shallow grooves extending from non-recessed portions of one edge of the first land zone to non-recessed portions of the other edge. The depth of the shallow grooves is less than the depth of the sipes.

A pneumatic tire is disclosed having a tread portion including a tread groove having a groove bottom and groove sidewalls. The tread groove has a groove width defmed as a shortest distance between the groove sidewalls. The groove has a groove length extending generally parallel to the groove sidewalls. A sequence of circumferentially spaced stone ejector ribs span between the opposed groove sidewalls.

A heavy duty pneumatic tire includes a tread portion provided with a zigzag central main groove having zigzag pitches of from 40 to 50. The central main groove includes a bottom and a pair of groove walls. Each groove wall includes a bottom side steep sloped portion and a top side gentle sloped portion. The steep sloped portion includes a height of from 10% to 35% of a depth of the central main groove and an angle of from 0 to 10 degrees with respect to a tire normal line of a tread ground-contact surface. The gentle sloped portion extends radially outwardly from the steep sloped portion. Each groove wall includes an internal corner protruding and an external corner, and the angle of the gentle sloped portion decreases in a range of from 15 to 25 degrees from the internal corner toward the external corner.

A heavy duty pneumatic tire includes a tread portion provided with a plurality of circumferentially extending main grooves and a plurality of land portions separated by the main grooves. The land portions include a shoulder land portion with a tread edge, a first middle land portion adjacent to the shoulder land portion, and a second middle land portion adjacent to the first middle land portion. The shoulder land portion is formed into a circumferentially continuous rib. The first middle land portion is formed into a row of first middle blocks separated by a plurality of first middle lateral grooves. The second middle land portion is formed into a row of second middle blocks separated by a plurality of second middle lateral grooves. Each first middle block has a circumferential length greater than that of each second middle block.

The pneumatic tire has a tread pattern including a plurality of ribs partitioned by shoulder primary grooves and a center primary groove. The ribs include shoulder ribs positioned at respective end sides in the tire axial direction in relation to the shoulder primary groove, and a center rib positioned at a center side in the tire axial direction in relation to the shoulder primary groove. The center primary groove has a plurality of groove-bottom protrusions formed intermittently in a tire circumferential direction. The groove-bottom protrusion is longer in the tire circumferential direction than in the tire axial direction, and all or a part of the plurality of groove-bottom protrusions exist on a line of extension of the axial groove.