Run-flat tire

A run-flat tire, comprising:

• a tread portion extending in a tire circumferential direction and having an annular shape;
• a pair of sidewall portions respectively disposed on both sides of the tread portion;
• and
• a pair of bead portions each disposed on an inner side in a tire radial direction of the sidewall portions;
• a carcass layer being mounted between the pair of bead portions,
• a plurality of belt layers being disposed on an outer circumferential side of the carcass layer in the tread portion,
• a side reinforcing layer being disposed on an inner side in a tire width direction of the carcass layer in the sidewall portions, the side reinforcing layer having a crescent-shaped cross-section,
• the carcass layer being turned up around a bead core of each of the bead portions from a tire inner side to a tire outer side,
• a first bead filler being disposed on an outer circumferential side of the bead core,
• a second bead filler being disposed on an outer side in the tire width direction of a turned up portion of the carcass layer along the turned up portion of the carcass layer,
• a first reference line, a second reference line, and a third reference line being specified such that the first reference line is drawn from a tire maximum width position along the tire width direction, the second reference line extends through a midpoint of a length along the carcass layer from an intersection point between the first reference line and the carcass layer to an end on an outer side in the tire width direction of the belt layers and the second reference line intersects the carcass layer at right angles, and the third reference line extends through a midpoint of a length along the carcass layer from the intersection point between the first reference line and the carcass layer to an end portion on an outer side in the tire radial direction of the first bead filler and the third reference line intersects the carcass layer at right angles, and a thickness G on the first reference line of the side reinforcing layer, a thickness G1 on the second reference line of the side reinforcing layer, and a thickness G2 on the third reference line of the side reinforcing layer satisfying relationships of 0.8×G≤G1≤1.0×G and 0.5×G≤G2≤0.7×G, and
• the side reinforcing layer being a uniform layer overlapping the first bead filler in the tire radial direction on a radially inner end of the side reinforcing layer and overlapping the belt layers in the tread portion in the tire width direction on a radially outer end of the side reinforcing layer.