Recent evidence suggests heterogeneous impacts of microfinance loans, with limited average effects on enterprise growth among the poor. One possibility is that the rigidity of the classic microcredit contract – widely held to be important for reducing default – inhibits investment in microenterprises. To explore these trade-offs, we provide experimental estimates of the consequences for client investment behavior of introducing a grace period before repayment begins. Delaying the onset of repayment by two months significantly increases both business investment and default. Taken together, the results are consistent with clients on the delay cycle choosing investments with higher expected income but more variable returns.