I have just had by new bike for several days but notice that one click of the bar end shifter doesn't mean one gear change like it did with my thumb shifters on my trek bike. Is this normal? I notice that between the second and third back ring I can't seem to get the chain to stay in the same place. I have to kinda tweak the bar end for it to stay in place. No problem witht the other gears. I was just wondering.