I am adjusting my rear derailleur indexing. It seems impossible to find the correct tightness. When I tighten the tension with the tension barrel adjuster, I have one of two problems: either it is too tight and the derailleur jumps from the third largest to largest cog (skipping the second largest cog) or it is too loose and does not want to jump from the smallest to second smallest cog.
I used the smallest turns imaginable to adjust the barrel adjuster, but still no luck. I kept the front derailleur in the middle cog (of three). Also, adjusting the B screw does not seem to have any effect.
There are nine gears.