if you're going to stick something inside your frame an absorbant material wouldn't be my first choice.
use motofoam or try to find the dedicated neoprene cable sleeves some manufacturers use to deaden internal cable noise.
I had cable slap of the hydraulic hose against the fork stancion on its way to the front caliper. I superglued a small piece of neoprene to the hose where it crosses the stancion. If you think it is coming from inside the frame slightly pushing or pulling the cable(s) where they enter the frame may cure it.
Your brake hose should not be routed anywhere near your stanchions.I had cable slap of the hydraulic hose against the fork stancion on its way to the front caliper. I superglued a small piece of neoprene to the hose where it crosses the stancion.
I meant lowers not stanchions!!Your brake hose should not be routed anywhere near your stanchions.
Re-route it.
A rubbing hose will wreck a stanchion in no time.
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