Stepped (plastic) ferrule of rear brake cable stop: Replacement and safety concerns
[I'm not allowed to post images because my account is too new, so those imgur links will have to do...]
While dragging my bike through some bushes, the exposed section of its rear brake cable running along the top tube got snagged in a branch and I ended up losing the small plastic piece that goes over the housing to turn the frame's cable guide (?) into a cable housing stop. I believe it's called a stepped ferrule or stepped housing end. Naturally, there is another such piece on the other end of the exposed cable, which I'm pretty sure is identical to the one I lost, so I can show you what it looked like:
My first question: What exactly is this called and where can I buy a replacement? Searching for "brake cable stepped ferrule", "brake cable stepped housing end", "brake cable stop" etc., I can find bits that look similar, but none that are an exact match.
My second question: Considering some bushes were enough to somehow dislodge or break one of these, I'm wondering how safe they are compared to alternatives like e.g. a fully housed brake cable or a different kind of ferrule (maybe made of metal):
That thin plastic step (see highlight in last pic of the album) has to withstand a lot of force and if it breaks the housing will just slide through the guide and the brake will fail.
The cable sliding out might also be a concern: I can see that rotating the ferrule gap to be opposite of the guide gap makes that unlikely and that even if they are aligned it's still unlikely due to the cable's tension opposing it, but I wonder if that's how I lost the other one.
What bike is it? I agree it seems bananas to put the stopping force on the ferrule when normally it is on a brazed on metal cable stop.
It's possible that its just a shit design. Maybe you can at least get a metal replacement ferrule? Full housing is another option as long as the cable stop by the brake isn't the same design
For what it's worth, you may not need a replacement piece at all. That piece should be able to slide over the bare cable, then insert the housing into the piece and the piece into the frame slot. Obviously I also don't know what to call the piece.
I either don't get what you're saying or didn't explain the brake cable structure of the bike well enough. It looks like this:
brake lever---housed cable---transition to unhoused via cable stop---unhoused cable---transition to housed via another cable stop---brake itself, more transitions there but that doesn't matter here
At each transition between housed and unhoused, I need one of these pieces (or something similar), but since I lost one of them, I only have one.
But as the other replies all suggested full housing instead of bothering with this ferrule thing, I think I'll just try that.
Don't know what it's called but looking at it gave me the same gut feeling as yours. This looks like a weak point I wouldn't want to have on my brake line. I'd go full housing myself. I've been doing full housing for nearly a decade now and when your cable is decent, the increase in friction is negligible. Sometimes it might even have less friction compared to having some of the cable stops having the cable exiting at suboptimal angle. Go with a full housing and stop thinking about it.
If you're buying new cables and you can afford it, grab some cables with compressionless housing. The difference they make in brake feel is really nice.