Originally Posted by Mr. Beanz
You do use the 53-15,16,17,19? What's the problem?
It's ok to use the big gear on a roadie and the middle on a hybrid. Off the top of my head, the 53/17 combo may be the same as the 38/13. So it doesn't matter if you're in a big ring or a middle ring if the gear inches match or are real close.
Maybe both these combos equal 65 gear inches. Just guestimating. Look at the chart and compare the gear inch combos.
See this is the problem, earlier you mentioned change the 39 to a 42, why? What does that get me? Besides more teeth, what the difference? This is what I want to learn about. How different size cogs or rings will effect my riding or performance. Once I understand that, I can then look at all the nicely configured programs that give me lots of numbers and have a clue as to what they mean.