Originally Posted by
big chainring
I've been running a Simplex front derailleur repaired with tubular tire rim cement for 8 months. Seems to be a permanent repair.
Never ever give up on a Delrin Simplex derailleur.
I would be looking for an adhesive that bonds acetyl type plastics, usually a two part system.
I have one that has typically cracked, I was going to bond it then bore two holes and run a long 00-90 brass machine screws into it (decent hobby store item), if I recall there is room to the inside of the M5 fastener.