Like everyone else before said. You're going at it wrong. Start from the beginning. Set the high/low limits (you don't need the cable hooked up to do those). If you want to, now is a good time to adjust the b-trim.

Then attach the cable with a moderate amount of tension after turning the adjuster all the way in, then backing it out about 1-1/2 turns. It should shift pretty well then and all it will need is minor adjustment of the tension to get it perfect. If you can't get it perfect take a look at the rear derailleur hanger and see if it's bent or loose.


Just go watch a good youtube video on how to do it and follow it step by step.

For fun, try this though. Unhook the cable completely. Now let the derailleur fall to the smallest cog.. does it make it? If not you have the high limit screw set incorrectly. Now push the derailleur all the way towards the spokes while turning the cranks, can you get the biggest gear engaged? If not you have the low limit screw set incorrectly. Turn it while holding the derailleur towards the wheel until you can get the bike into the biggest cog.

If you don't do that properly then you'll never get the derailleur into all the gears no matter how much you adjust.

http://www.parktool.com/blog/repair-...nts-derailleur