Why is inflation pressure so important in bicycle tires?

Only a tire with sufficient inflation pressure can bear the weight of a bicycle. The higher the inflation pressure, the lower the rolling resistance and higher pressure also reduces the likelihood of a puncture. Long-term, under-inflation often leads to premature tire wear and aging, commonly resulting in sidewall cracking and increased tire wear. On the other hand, an under-inflated tire absorbs road shocks better. Wide tires are generally used at low pressure. The advantages are that the large air volume absorbs road bumps and holes without the drawbacks of high rolling resistance, less puncture protection and tire wear.  more