not much you can do with them, the return spring is responsible for pulling them back apart, and it's probably gone a bit, being old. you can dismantle and clean the thing, maybe some light oil on the pivot (but not so much it leaks out and goes on the rim!)
the truth of the matter is they ain't much cop compared to modern dual pivots which you can pick up for £10.
yes, they are shit.
not much you can do with them, the return spring is responsible for pulling them back apart, and it's probably gone a bit, being old. you can dismantle and clean the thing, maybe some light oil on the pivot (but not so much it leaks out and goes on the rim!)
the truth of the matter is they ain't much cop compared to modern dual pivots which you can pick up for £10.