Originally Posted by
Salamandrine
That front derailleur is very poorly positioned. The cage should be rotated a bit and the derailleur repositioned so that the changer is evenly spaced from the chainring. Gap should be ~1/16-3/32" Do not overtighten the clamp though, that's the part that breaks --leading to the simplex derailleurs are weak myth.
Simplex delrin derailleurs' bad reputation
might be a little bit overblown, but I'm convinced they ARE weak or that they can become brittle with age. I've seen more cracked than intact fronts in the wild. I have a Peugeot and a Follis in the garage, both from the early '70s, both of which came with Simplex delrin derailleurs. The Follis' front derailleur was gone, except for some of the clamp that remained on the seat tube. The Peugeot's was intact, but it looked like years of UV exposure didn't do it any favors. The Peugeot's
rear derailleur body was cracked. Between the two bikes, only one derailleur pulley hadn't cracked and lost some teeth. Two bikes is an admittedly small sample size, but sometimes it only takes a small sampling to draw conclusions. Some people have obviously had better luck with them than I have, but I don't trust 'em.