Mudguards Rubbing

[colinr]

(this should be in Know How, can someone move it?)
I've fitted SKS Chromoplastics and they have 6-7mm clearance either side of the tyre but the plastic bit (see photo) knocks against the tyre quite easily on rougher roads and makes a lovely trilling sound as it deflects off the tyre wall.

Not sure if some rub is to be expected or not, never had "proper" mudguards before. Or do I need to adjust it so the plastic bits are completely clear of the wheel at the back?

 

[amaferanga]

What is that plastic bit? I've not used SKS guards in a while, but none of mine have that plastic bit. Is it something to do with the reflector?

But even the stay looks very close to the tyre - looks like you need narrower tyres or wider guards.

 

[colinr]

The lighting is deceptive, I can fit my finger with room to spare between stay and tyre.

Mr plastic bit is to guide the stay through the metal bracket on the guard and stop it rotating.

Guards are suitable for up to 28mm, and gators are fairly narrow as 28s go, so I'm sure this can work. Somehow.