How to tighten Fiamma bike clamp joint?

[maxstu]

Gone a bit loose. Any ideas how to tighten where metal meets plastic.... yet still keep 360 articulation.
Ta Stuart

[RogerT]

Sorry for being late to this particular party, but I’d suggest some tender loving care, as afforded by a delicately wielded appropriately sized hammer (I.e. quite a small one) working round the crease.

[maxstu]

Sorry for being late to this particular party, but I’d suggest some tender loving care, as afforded by a delicately wielded appropriately sized hammer (I.e. quite a small one) working round the crease.

it was getting a bit lonely, Roger...
Tried this method. The metal is surprisingly tough. And the plastic somewhat brittle. Im a bit ham-"interfered with" so concerned the wrong area may fracture if I start giving it some welly.
Tried pinching with a chisel..nothing.
I might try filling the void with non hardening bathroom sealant for a shot in the dark.

Party ON!!

[itchyfeet]

I suggest you dribble some thinned varnish or paint into there.
not enough to glue it solid.

[maxstu]

I suggest you dribble some thinned varnish or paint into there.
not enough to glue it solid.

Another good suggestion..thanks

[937carrera]

Unscrew the red knurled knob
Open the clamp
Take a flat file to the face that you have just exposed
Remove material carefully until it clamps tightly enough again

I suspect it's either wear on the top pin increasing the diameter, or corrosion on the bottom face giving the same effect.

[itchyfeet]

Unscrew the red knurled knob
Open the clamp
Take a flat file to the face that you have just exposed
Remove material carefully until it clamps tightly enough again

I suspect it's either wear on the top pin increasing the diameter, or corrosion on the bottom face giving the same effect.

I think he means it is loose where the metal tube is pinched onto the plastic clamp, so would not stay in position when bikes off.

I might be wrong though

[937carrera]

I have a bike rack, but not a Fiamma one, or at least it is not exactly the same as Stuarts.

I read it as an inability to clamp the tube sufficiently when it is inserted, so either increase tube diameter or reduce clamp diameter. Maybe he has the solution to a problem he doesn't have yet.

[maxstu]

Wobbly socket betwix plastic frame holder and arm is the issue

[diabolov]

Try a centre punch instead of a chisel it will concentrate the force to a point rather then
along the chisel face. A blow on opposite sides to see how you go then maybe on the quarter
turn too....

OR drill and tap the tube, then a small screw to pinch the plastic bit ?!

Regards

M

[maxstu]

Try a centre punch instead of a chisel it will concentrate the force to a point rather then
along the chisel face. A blow on opposite sides to see how you go then maybe on the quarter
turn too....

OR drill and tap the tube, then a small screw to pinch the plastic bit ?!

Regards

M

Good point. Grub screws either side to add a bit of pressure

[diabolov]

Or a star head clamping knob

M

[itchyfeet]

Good point. Grub screws either side to add a bit of pressure

This has to move right? so a grub screw will just gouge out plastic as you move it then become loose again, if it were fixed you could just put a bolt through.

[937carrera]

I've been a bit slow on understanding the problem, is it that the deformation in the (metal) tube that holds the (plastic) clamp in place has slackened and is now wobbly ?
See the picture attached

The issue with pin punch marks or grub screws is that they may stop it rotating and create new wear, when I think you still need it to rotate through the 360 degrees. I'm going to assume there's a groove on the plastic which has worn.

What you need to do is to reduce the diameter of the tube, but all the way round. What you could do is to put something in the groove and "almost" all the way round, and then use a jubilee clip to compress the tube further. Think of it a bit like like a piston ring compressor acting on a ring

[937carrera]

Resized to make the picture visible - sorted yet ?