Originally Posted by
Spaghetti Legs
If you take a close look, a lot of used Campy rear derailleurs from the 70's-80's will have Suntour or Shimano jockey wheels.
This is because they are exactly the same size and cheaper - not because they were any better. You can presently buy better idler pulleys from China for $4 a set. They do take forever to get here.