Join Date: Apr 2009
Location: New Rochelle, NY
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Mentioned: 11 Post(s)
Tagged: 0 Thread(s)
Quoted: 558 Post(s)
I suspect that it's a stop to keep the RD from swinging back too far when you remove the wheel. The front side will engage the stop tab when you pull the RD back (or when the upper body spring on some models does so). It's probably cracking from a bit of hard banging into the stop tab, but it's hard to tell from the photo.
An ounce of diagnosis is worth a pound of cure.
“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin
“One accurate measurement is worth a thousand expert opinions”
- Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance