I had been having trouble adjusting the rear derailleur on my Kona Caldera I won at an auction a couple weekends back. Turns out the derailleur hanger was bent. I removed the hanger from the bike, put it in a vise, and straightened it out with a wrench. But now, when I close the skewer, the hanger is flexed towards the wheel, and in turn misaligns the derailleur. So, what can I do about this?