As far as I can tell these exist just to make routing the chain wrong. It seems every derailleur has one. It doesn't connect to the other side so it's not stiffening the cage. Why?
by PCLoadPLA
As far as I can tell these exist just to make routing the chain wrong. It seems every derailleur has one. It doesn't connect to the other side so it's not stiffening the cage. Why?
by PCLoadPLA
11 Comments
The chain is misrouted in this example — this is a common mistake.
The tab is there to still chain whiplash — if it swung far enough, it could twerk it off the guide pulley.
Helps keep the chain from bouncing around and getting jammed between the jockey wheels
I think its to stop chain bounce?
My guess is that it’s there to prevent a complete collapse of the two sides of the cage that would prevent chain movement ,Like a stop . In the event of a crash or the bike tipping over. I could be completely off but that’s how I have always looked at it.
I believe your chain is routed incorrectly.
So that all of us can make that mistake once!
More seriously, they are simply to help keep the chain on the pulley wheels by limiting the ways the chain can bounce around.
You have your chain routed incorrectly. Using this photo as reference, you need to put the chain on the right side of the tab.
It’s to help secure the chain, but I’ve used some old danglers that don’t have this tab and never had issues, even riding loaded on gravel forest roads.
So probably it’s an instance thing, like lawyer tabs.
So you can screw up and route the chain incorrectly.
So you can post here and ask “what’s this noise?”
Helps to identify shoddy home mechanics.