I ran the math on your gears. A Downtube 9FS has a 20 inch (406) tire, a 9-speed 11-12-14-16-18-21-24-28-32, and a 48T front. Sheldon says this comes to 28/32/37.4/42.7/49.8/56/64/74.7/81.5 gear inches.

At the low end your biggest jump (16.7%) is from 28 (second hardest) to 24, resulting in 32 to 37.4 gear inches. That's not all that bad. You could change your larger gears to be closer together. For example, if you did a "Century Special" (13-14-15-17-19-21-24-27-30) you could see some more options at the low end. But beware that you're going to *really* sacrifice your high end.