I have a hybrid 18 speed bicycle which is able to shift through all gears on both the front and rear sets of gears. When on the largest gear on the front set (by the pedals) the chain will try to slide to the next smaller gear when pedaling backwards. It is as if the chain in bent or not moving in a spot.
There is also a cyclical click when pedaling forwards in higher gears with an occasional slip. It seems the chain may be uneven in several links.
What is the most likely cause/fix for this?