Originally Posted by
rydabent
The fact remains that if you turn your pedals backward, or roll the bike backwards and gears change, something is misadjusted. Either the hanger is bent, or the RD is not adjusted right.
As FB said, "no". When pedalling or rolling backwards, the chain action is at the top of the cassette, where there is no derailleur to guide it, so it tries to "settle" into line with the front chainring. But since the derailleur is still in the original spot, the chain will get resistance as it can't engage the derailleur pulleys properly.
Lean the bike up in 1st or 2nd gear, slowly back pedal by hand, and you can see it clearly.