Okay--I just don't understand the math part of what I can intuitively understand when I try to climb a hill under full load. I have a humble Norco Monterey--and he sure needs an edge for those hills--as does my resected lung. So--what I need is more oomph for going uphill. Can someone give me a very simple explanation of what I will ask the mechanic to do--to change those cogs and such--to achieve the end result of easier hill rides? Thanx