My bike has a 52-42-30 triple crankset in front, 170mm arms. The cassette is 9 speed, and thus for the purposes of this question, non-negotiable (due to expense of swapping out my entire drive train).
Apparently the 52-42-30 is an extinct beast, which is annoying enough because any replacement rings do not work nearly as well as the original did in terms of smooth shifting and propensity to drop chains or get chainsuck.
However, I am struggling with chondromalacia and since raising the seat only made the back of the knee sore, I cannot use that to reduce compression of the knee joint. So, I am looking at getting a triple with 165mm cranks. It looks like 50-39-30 is the new standard for triples (I use triples because I need the increased q-factor). This would likely necessitate a new front derailleur, but I am not sure.
What would be a cost effective solution to getting shorter crankarms and still have a triple? Links, specific suggestions, etc will be greatly appreciated.