I couldn't agree more Scotchmo, Sprockets that small put violent stresses on the chain at high speeds and small sprockets wear quickly. That's the method they use to get one stage reduction on pocketbikes. They went to a smaller pitch chain so the smallest sprocket has a couple more teeth at least, and is still able to get a good amount of reduction.
You don't have to lose your pedals if you place the jackshaft behind the seattube above the bottom bracket (crank bearing housing). Give us pictures or more details about your frame.