Originally Posted by
Viich
I meant that no one had described the effect - that the chain going slack in small-small is all that happens...
Fourth post:
"Long cage derailleurs exist to handle wide gearing ranges. When you shift from your biggest chainring and/or cassette cog to smaller ones, the chain would hang slack if it wasn't for the spring-loaded cage on the rear derailleur. The longer that cage, the more slack in the chain the derailleur can take up, and thus thus the wider the gearing range the derailleur can handle."