As noted, Allbirds are impressively durable when it comes to everyday wear. In a heavy shoe rotation, most Allbirds shoes will survive at least 8 - 10 months. At the same time, some reviewers report wearing Allbirds Runners casually for over two years, with only a few cosmetic flaws developing later on. Ultimately, the sole will wear down over time. Still, the SweetFoam midsole takes the sting out of this a little, as the sugarcane-based material is completely renewable, as well as being carbon negative.