Originally Posted by
jisho
I'm currently in the preliminary stages of building a touring bike. My thoughts for the drive train include a Shimano XT 10 speed setup. The LBS guy advised that I should go with a double as with this setup the ratios are the same as a triple if one gets the rear cogs right. I haven't done the math and wonder if this is true? Any advice would be helpful.
Thanks
Do the math, or let Sheldon's Gear Calculator do the math. There's no reason to not know what you're doing. If you aren't carrying a heavy load and you're young and fit you could do great with a double and an eight or nine speed cassette. Just guessing the price difference might be $300 or so between good enough eight/nine and ten speed setup. Long time ago a triple was the only practical way to get low gears with a 14-28 five speed freewheel, 8 spd double can give you the same range.
http://www.sheldonbrown.com/gears/