Suggestions on SS mtb gear ratio?

I've been riding a SS mtb around with a 34-tooth chainring and 15-tooth cog. It's fine for riding around Forest Park and it's climbs but I fear it's too high a gear to do any "real" climbing. Plus, I would like to take a stab at racing SS.

Ideas on what my gear combo should be to be competitive or at least not kill myself?

Thanks.

-will