I don't know what issues you are having. Have you ridden it yet, or just setting it up? If setting it up, make sure your derailleur cogs are perfectly in line with the high and low cogs of your cassette through the range of the shift lever. When you shift just move the lever slowly until it shifts into the next cog. I find it easier to get perfectly aligned shifts when going into a lower gear. It's like driving a stick shift. You will have it mastered in no time. Good luck.