My friend’s old Trek shifter boss fell off..

[shinomaster]

This is an old Aluminum frame with a steel caboose I believe.. circa 1989 ? This kid was probably born in in 1984 so he's not the original owner fwiw..

[ultraman6970]

I could swear I put this link in my asnwer.... this is the best looking and simpler solution of all IMO.


https://www.cycle-frames.com/bicycle...-AL-FRAME.html

[Hindmost]

A lot of viable suggestions here. I would be tempted to clean up the surfaces and epoxy thing back on. What have you got to lose?

[charliedid]

Originally Posted by Hindmost

A lot of viable suggestions here. I would be tempted to clean up the surfaces and epoxy thing back on. What have you got to lose?

I'm in your camp. Glue it...

[shinomaster]

Originally Posted by charliedid

I'm in your camp. Glue it...

I'm down, which epoxy?

[Hindmost]

I was hoping some expert would weigh in. I've used J-B Weld on aluminum successfully. Important to fine sand surfaces to fresh metal and wipe off residues with acetone.

[bikinchris]

Originally Posted by shinomaster

I'm down, which epoxy?

More important than the epoxy is the preparation of the surfaces to be glued. The right finish and as clean as humanly possible, then glue it and clamp it tight until it has set up!

[charliedid]

I agree with the two answers above.

[oldpotatoe]

Originally Posted by classtimesailer

Epoxy.
Drill a smallish hole in the down tube, clean everything well, and glue.

This...

[classtimesailer]

Do not clamp it which would squeeze out most all the epoxy.
You need the layer of epoxy between the parts.