Sorry about the links not working. I need to make sure they work before posting links in the future. As to your current crankset (FC-M530), it came in 2 configurations, 44-32-22T and 48T-36T-26T. You can't get any lower than 22T small chainring. If you have the "larger" configuration, you could change just the 26T inner with a 22T and not notice much if any difference, other than the lower gearing. These are standard 104/64 mm BCD 4 arm cranks so chainrings are still readily available (about $8 for an alloy 22T, $11 for a steel 22T). As to the rubbing in large large- other than annoying, how often are you in that combination? Could save a lot of money not buying anything if you realistically never use that combo (except downhill with a tail wind).