Originally Posted by
Trakhak
Most bikes can tolerate backpedaling if the chain happens to be on a chainring/sprocket combination reasonably close to being in the same plane. Some bikes with long chainstays can tolerate moderately offset chainring/sprocket combinations. So what? Why anyone cares about backpedaling defeats me.
In a friction system can help determine if rear derailleur needs slight adjustment as one coasts up to a stop. Particularly useful on a tandem when things are too far back to see or hear. With a quick 1/4 to 1/2 gentle backpedal one can usually feel a misalignment and take corrective measures.