Quote from Tom Nuchols on Aug 20^th, 2011, 5:16am:

 
 Does it have bar end shifter?? If so that what the prob is , same what it was doing on my trike...

I had this problem once. I did some reading on it, and found that the shifter cable tension regulates the sensitivity and speed of the shifting. There on the handle bar where the shifter cable enter the shifter housing, there is a nut around the cable that makes small adjustments to the tension. I found that I could adjust this easily while I was riding - I found the sweet spot and my bike stopped shifting gears by itself. It's hard to climb a hill when your bike keeps shifting gears, isn't it! Oh yeah, the adjuster screws on the rear derailluer are for setting how high and low the chain will go, they don't affect how it shifts on the cogs in between. As long as your bike will shift onto the biggest and smallest cogs without throwing the chain off, leave these screws alone. Good luck!

Quote from Tom Nuchols on Aug 20^th, 2011, 5:16am:

 
 You will prob still have the same prob because what you describe is indexing wasn't right .A loose chain will jump up not change gears .

I had a similar problem on my trike. It made climbing a real adventure. I couldn't find an adjustment to consistently correct it it but Mike (Easy Street) finally fixed it by adding an extra spacer to my cassette.

Thanks for every one inforumatgion.
 
The chain was definitely worn out.  The gauge fell in the 1.o slot like it had molasses on it.   The Cassette nut was definitely tight.  
The new 951 chain is installed, and now for the adjustments.    
I am having a hard time understanding why the old 971 chain wore out so fast.  I t did not have many miles on it.  I had changed the  
chain on the Home built bike at the same time an it has a lot more hard miles on it than the  Bacchetta did.
5/8 inch of rain last nite and the air sure is cool and nice.
Thanks again.
Tom Nuchols