Gear Inches
I ride an older touring bike and I'm working towards riding when I'm able to. I understand gearing based on how many teeth the chainrings have and how many teeth the cogs have, so for me a small ring of 22 is good and the lower the cog on the back the better for climbing.
I hear talk of gear inches and so far I'm confused by it. How do you figure out how many gear inches your bike has in a given combination? Is there an easy rule or do you have to crunch some numbers?