Lubricating plastic eyeball vents

[pa38112]

Has anyone found a good lubricant for the vans plastic eyeball vents? Mine seem to stick when they get hot in the sun and are impossible to turn.

[rzbill]

Arai Helmets give a tiny jar of lube for the plastic bits (like the shield hinge). I have always assumed that this was a silicone grease. Not sure where to get something similar. Could try a silicone spray. That should be available at a Home or Auto DIY store.