Fractional reserve banks can only increase the supply of fiduciary media by (a) lowering their reserve ratios, or (b) acquiring more base money. In a free banking situation, where there are no laws restricting competition between banks, no deposit insurance or "lender of last resort" insulating them from the effects of their poor decisions, and where the base money is gold, there is a limit to how low banks' reserve ratios can go, and there is no way for banks to obtain more base money except very gradually through newly-mined gold entering the system. In other words, in a free banking situation, there's a strict limit to the ability of fractional reserve banks to expand the money supply. The whole problem is government interference in the banking system, not fractional reserve banking.