I'll have a look tomorrow, internal stops hadn't occurred to me. There aren't any end caps on there as the entrance must be barely more than 5mm. Standard brake cables are a squeeze getting in. I had thought a step down ferrule of some kind might be solution because a standard stop won't fit in. I'll update what I find shining a torch down there
Stepdown ferrule may be the answer, if there's nothing stopping the end of the cable over time the metal inside the outer can work its way out of the sheath.
I'll have a look tomorrow, internal stops hadn't occurred to me. There aren't any end caps on there as the entrance must be barely more than 5mm. Standard brake cables are a squeeze getting in. I had thought a step down ferrule of some kind might be solution because a standard stop won't fit in. I'll update what I find shining a torch down there