Originally Posted by
shelbyfv
The triple crank will also require triple compatible shifters and front and rear derailleurs. Your simplest and least expensive path to significantly easier gearing will be a "compact" crank, usually 50-34, and a larger cassette. You can probably use a 28T or 30T w/o changing your rear derailleur. Plug those numbers into you calculator and see if it gives you what you want.
This.
I run a 50-34 crankset with a 11-32 cassette on my road bike. You have to check what's the maximum cassette your RD can take though.