Abstract: A spare tire which is expandable by inflation, having a radial carcass reinforcement anchored to at least one bead ring in each bead and having a tread reinforcement formed of at least two plies of cables which are parallel in each ply and crossed from one ply to the next and form acute angles with the longitudinal direction of the tire, is improved due to the fact that the plies are composed of cables whose elasticity decreases as the inflation pressure increases and as the tire passes from the collapsed condition to the expanded condition ready for travel.