I had this fault with a Peugeot PY10 FC (Vitus). I used some 3M adhesive but it eventually broke again.
I used a ratchet strap to pull the frame open to access the lug. You also need to clean the surface thoroughly. The adhesive must have a very high peel strength.
Personally, I'd sell or bin the frame. It's not nice riding something that might potentially break more easily during use.
I had this fault with a Peugeot PY10 FC (Vitus). I used some 3M adhesive but it eventually broke again.
I used a ratchet strap to pull the frame open to access the lug. You also need to clean the surface thoroughly. The adhesive must have a very high peel strength.
Personally, I'd sell or bin the frame. It's not nice riding something that might potentially break more easily during use.