1

I'm having a lot of trouble finding short brake cable ferrules. The ones I've found are all long and tapered as in the picture below.

I don't understand the purpose of this design. The brake housing only fills half the ferrule, so the cable is effectively rigid for an extra centimeter. The housing is also loose because all the ferrules I have in this style (various brands) measure 5.2mm internally on the female side. The tapered end is loose in the cable stops on my bike and doesn't fit my mountain V-brake shifters.

What's the point? Why are the only short brake ferrules available the cheap crimp-style?

Brake cable ferrules

Shift cable ferrules

Alex
  • 301
  • 2
  • 13
  • Higher forces encountered on brake housing versus shift housing. Longer ferrules adds support to the housing – Rider_X Jul 08 '17 at 00:05
  • That doesn't make sense to me. The housing doesn't require extended support, only a hard edge. Why this particular shape and sloppy tolerances? – Alex Jul 08 '17 at 00:33
  • Brake cables can suffer from a sharp bend where they exit the braze-on. Remember many brake cables are spiral-wound, and sharp bends impact their performance and durability. So longer ferrules help stop them kinking. In terms of safety, I'd rather have an overbuilt brake system than an underbuilt one. – Criggie Jul 08 '17 at 02:18
  • Are you crimping the ferrules on or just leaving them loose ? If you don't like the marks made by compression crimp then you could use some kind of adhesive perhaps inside the lip? (ie nowhere near the cable) – Criggie Jul 08 '17 at 02:19
  • @Alex it's pretty rare to have a straight run of cabling, as such cable housing is usually laid out with arcing bends which results in flexing when braking or shifting. The stress can be more extreme at an immovable connection point (i.e., cable stops), especially as this is usually at the end of an arc bend. This can result in accelerated wearing and kinking of the housing. A longer ferrule helps stabilize the housing in this high stress area. It also can reduce flex making brakes more responsive. – Rider_X Jul 08 '17 at 03:14
  • Are you supposed to crimp ferrules like that? I thought they were supposed to have a slight interference fit. (True, it seems, for 4mm cable, but not for 5mm?) Also-- as soon as the housing exits the ferrule, it bends. Worse, even, because there's less housing to work with. Is there a picture illustrating the problem they're intended to prevent? – Alex Jul 08 '17 at 05:29

1 Answers1

3

Stepped brake ferrules, the long type you mention, exist for using 5mm compressionless (aka braided) brake housing on levers and brakes that have a plain 5mm bore, intended to take conventional spiral brake housing without a ferrule, such as many brifters and road calipers. You must use some kind of thick-ended ferrule with compressionless brake housing, or else the wires will pull through, same as using compressionless shift housing without a ferrule. Using them elsewhere, such as housing stops, is basically incorrect.

If you want more premium 5mm ferrules than the commonly encountered plated ones, a couple companies make them, Wheels Mfg and Jagwire for example.

Nathan Knutson
  • 84,914
  • 3
  • 90
  • 214
  • That mostly makes sense. I don't own a true road bike, new or old. My hybrid and mountain bikes don't fit those ferrules.

    But then, neither does Jagwire KEB-SL compressionless housing. It's the same diameter as the normal stuff.

     – Alex Jul 08 '17 at 05:26
  • KEB-SL kits come with Jagwire POP ferrules, the most commonly seen example of stepped ferrules. It fits, I use them together pretty often. – Nathan Knutson Jul 08 '17 at 05:46