Originally Posted by eric von zipper
i was wondering about that, the cassette that is. i saw on the harris cyclery website that there are custom made cassettes: Cyclotouriste, but they are v. pricey. would having a 13/15/17/19/21/24/27/30/34 cassette (or something in that vain) and the 30/42/52 crankrings up front be ok for touring?
i need to learn about gear inches and ratios and that stuff...it's all alein to me right now.
Sheldon Brown has already covered quite well
here. Use his gear calculator and run the numbers. A 30 for the low on the crank is too high for my tastes. I also think that the jump from a 24 to a 42, while doable (probably) is too big. A 40 middle would be better but you would have to change 2 chainwheels as well as the cassette to get that. Chainrings run around $30 each and the cassette is about $100 for the custom one. Might just be easier to change the chainwheels and pocket the extra $70.
One note on the gear calculator: If you change a number on the gears you want to look at and just recalculate, it will add it to the results page. That way you will be able to compare all kinds of ratios.