I've got a 10 speed Record T triple crankset, that came as 50/40/30, along with a 12-27t cassette. In my quest for low gear nirvana, I replaced the 27t with a Miche 30t (BikeInn, about $8), and that helped. Since I am a hill weanie, I knew that I could squeeze the beasty to yet new lows. So a trip to my fav bike co-op, my happy place, garnered me a $2 Shimano 24t chainring, 5 bolt with a 74mm BCD.
The 24t chainring went on in place of 30t without a hitch, and I took out 2" of chain, as the decrease ring diameter left the wrap too loose in the back. After adjusting the B tension screw thingy all the way out, I got the derailleur pully to just clear the 30t cassette cog.
There are demons however, as I can't shift big-big without buying spare long cage rear mechs. But then if shifted like that, I would be stupid, right? And we all know that my brane wurkz jsut fiine, eh? The shifts from mid-low ring are smooth, with no drop (so far), and low-mid seem good, with slight hesitation but no major issues. Major testing ahead, before I can claim victory. Just wish I had this for the 5,000' of climbing during the century I did last Sunday!
So, risking the irritation of all the Campy experts, who are muttering "Tch-tch" as they read this, I now have a real hill climbing gear setup, with a low gear inch ratio of 21.5.
Almost low enough
Lemmee hear your low gear stories !