exRunner...
You previously stated: "I have riding buddies that say they can not tell the difference in those jumps. I can feel the 3% difference. I detest the 39 ring for that reason. I just don't feel comfortable."
What that I believe you're saying is that you prefer a larger jump between cogs (9% versus 6%). That's just the opposite of what most folks complain about. A lot of riders want an 18T to get a meager 5% jump (not me). Unfortunately, the percentages jumps have nothing to do with the chainring you're in. It's all about the cogs and you can't change the percentage when there's onlu 1T involved. Every shift has a different percentage, starting with 8.3% at the 11-12 and getting smaller.
I know that you feel it's OK to use all 10 cogs with the big ring. I don't, but then again, I use ALL of my cogs with the little ring on nearly every ride into the mountains. It seems like you should just toss your little ring or try a 42 if it's seldom or never used. I rode for 20 years in the moderately rolling terrain around Kansas City. I've know at least one Tri rider who never had a little ring and that was back in the days of 7-8 speed. Those guys could motor on the flats, but I'd always pass them on the the hills.
Last edited by DaveSSS; 10-31-09 at 07:52 AM.