cycles per second
Join Date: Oct 2003
Bikes: Vitus Aluminum, DiamondBack Apex, Softride Powerwing 700, "Generic" Ishiwata 022, Trek OCLV 110
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I understand what you're trying to do. I bought a used 5-arm "micro" triple crank (94/58mm BCD) and put Ritchey 44x29 "2 x 9" rings on it and use it on my commuter/tourer with an 11-28 cassette (or 11-34 for mountainous touring).
But can you do it with 104mm BCD Hollowtech II cranks? I dunno. Can you even get a 30T ring for one of those? If you find a Hollowtech II crankset with those rings, do they even sell them without BB cups, and if so, would the crank even work in your current BB cups? And can you lower your front derailer enough for a 6T drop in the big ring? It's about 2mm per tooth so a 6-tooth change would require lowering the FD by about 12mm (almost 1/2 inch).
If you have gears low enough, I'd stick with what you have. If you need lower, I agree with Rick on the wide range cassette.