Unfortunately, Delrin is stronger than anything you can bond it with. Also, the part broke where it did because that is the area of highest stress in response to tightening, so any attempt at bonding will be tested mightily, and when it fails, will almost certainly do so abruptly, if not during tightening. This could lead to consequential damages if it occurs during spirited riding, with a variety of possible "interesting" outcomes. I recently bought a mint white UO8 with a half-split front derailer body, but I just left it on there and never tightened the bolt. It only cracked as far as some '70's owner had overtightened it, and seems to have stabilized. I have finally sourced a good 28.0mm replacement. Note that these bodies crack over a relatively large section of material, there's no real weak spot on these unless one expects to torque it up like it's metal.
David Snyder
Auburn, CA usa
> The Simplex front derailleur body on my PX 10, which is made from the
> space age 1960's plastic known as Delrin has broken where the seat tube
> clamping band(metal)pivots. I have tried to repair this with JB Weld
> but the JB does not bond to the Delrin. Any sugeestions for a repair or
> better yet does anyone have a replacement derailleur body or complete
> (parallelogram type) Simplex front derailleur for sale? thanks and
> Merry Christmas to the CR list, Rod Handsfield, Wichita - where I did
> 20 miles on my Falcon San Remo fixie today, Kansas.