Hi Roscoe, I answered you in the other thread but will explain here.

I have an older mtb that had 13-30 7 speed rear and 24 34 44 front gearing. Ok most of the time but when loaded for touring I could feel myself cranking up steep hills. In BC we have not only steep hills but sustained steep hills so for me it got a bit much on my knees. Plus I like to ride gravel logging roads that have steep grades. BTW, Ithink the Duffy Lake road is one of the steepest sustained grades in N.A. and would hate to ride up it - down is another story!

I could have tried to swap out the rear cassette for something like a Shimano mega range which I have done in the past, but then you get a big gear jump. Instead I found a SRAM 22 32 42 crank that lets me keep my evenly spaced rear intact. I had to swap bottom brackets for a narrower axle but it works with my current derailer fine.

With a 7 speed you don't have a lot of options in the rear because of the large gear jumps that result from trying to create too wide a range from high to low. With a 9 or 10 speed cassette you can probably create a smoother transition from high to low there.

This weekend I took my loaded bike up and over the Malahat and could really tell the difference with the 22 granny. I'm happy but you need to take your time and think about what will be involved with either a front or rear gear swap. You could need a new front derailer, BB or axle, shorten or lengthen chain and rarely a new rear derailer. Mostly, if you can just swap out the 26 for a 22 granny it's a pretty easy swap that gives you that edge without affecting your higher gear range but you have to see how much the then reduced chain length effects the rear derailer.

The other comments about compatibility are correct. I had a 22 chain ring but it would not mate to my original crank. I bought my new triple crank for $66 and BB for $25 so less than $100. But that is old 7 speed technology that is cheaper than modern stuff.