We live in Pa with many hills, valleys uneven ground. My question is will a larger sprocket give fewer revolutions therefor more power and slower speed ?
We recommend directing technical questions toward the manufacturer or a local bike shop. Generally speaking, you can gear up by using a smaller rear sprocket or a larger countershaft/front sprocket. Gearing up adds more speed and decreases the final drive ratio. You can gear down by using a larger rear sprocket or a smaller front sprocket. Gearing down reduces speed and increases the final drive ratio.
That being said, we do not have any technical support here that can really go into depth on how that works. If this sprocket will work for you, customer service can help you order over the phone at 1-800-798-0325, or you can order online anytime!