Model is Senheiser Momentum2 HD1 Bluetooth (over ear) PF edition.
I have wrapped electrical tape over it but cables on both sides have started to disintegrate/decompose.
I know next to nothing about audio cables. I care more about functional quality then original looks so i would be willing to swap the entire cable for a more permanent one, but i wouldn't want them to look ugly either and need to find a good way to fit them to the earshell.
I had a similar thing happen to my HD280s. I replaced the cable with a mono 3.5mm jack on either earcup so that I didn't have to deal with it again. EDIT: I see yours are bluetooth. Do you know why they broke? You'll want to make sure that can't happen again before you do any big fixes
They just kinda started to decompose out of themselves. A bit like apples “environmental friendly” cables.I think the material got weak over time and because of repeated movement on the spiral caused it to tear.
What kinda freaks me out is that it doesnt look like any wire i’ve ever seen. The inside appears made of some Blue sticky stuff and there are single strands of copper wire floating inside that mess.
Ive never modded a cable and i know audio is particularly sensitive some i am a bit worried.
In addition to the advice from @beeng@discuss.tchncs.de, I would also say that stranded core, silicone wire will be the most flexible and will be more than durable enough. You shouldn't need too thick of a wire gauge. AWG 20 should be more than adequate.
Just get some thin 2 wire cable, and replace, you can essentially use whatever cable you want. It may not be shielded, but it will work just the same. Even inside of Ethernet cable is good usable wires.