avhed

For the road.
Like my Nuovo Record cables from the 1970s/80s.

3alarmer 

.
...too much extra weight.

davester

I'm also one of those folks who is skeptical of the newer, skinnier cables. I had a front brake cable snap once many years ago, as I careened down and crashed on one of the steepest descents in the Berkeley hills. Ever since then I have always specced the most expensive, thickest cables I could find (Campy for many years, lately Shimano Dura Ace).

Salamandrine 

Yeah, those thick and non-stretchy cables were once part of the Campagnolo experience.

It must be to make room for the plastic lining mostly. It could also be to increase flexibility for 'aero' routing along handlebars, as well as to save money for the manufacturers, of course.

1.8mm cables are still made for the BMX crowd, apparently.
https://www.amazon.com/Slic-cable-br.../dp/B000WYAF54

corrado33

First time I've ever heard of a brake cable snap. What it due to neglect? (No offense intended) And didn't you have another brake?

A properly taken brake cable shouldn't ever snap. Period. And that's simply from a legal standpoint. No cable manufacturer wants to get sued because their cables snapped and killed someone. I bet that a standard brake cable can easily handle 10x the largest amount of tension ever put on it by a brake before it even starts to fatigue. I forget what that term is called in engineering. Purposely over engineering something. Leeway? No... I forget.

Besides, those 1.8mm cables are awful to work with and require special everything to make them work. They're not necessary.

T-Mar

Improvements in technology and metallurgy has likely allowed elimination of some of the bulk and stiffness, while retaining the strength and low elongation.

davester

This was many years ago, and I was a poor student so I always bought the inexpensive parts, including cheap brake cables (a cable's a cable, right?). I assure you that the cable snapped all of its own accord. I'm not sure what neglect would be on a brake cable other than ignoring a frayed cable (I never noticed any fraying). The cable gave way at the cable tip/ferrule inside the brake lever leading me to suspect that the connection had been defective. The hill (Lomas Cantadas for you Berkeleyites) reaches 20% grade and I was moving fast so I was squeezing the levers extremely hard, which I'm sure was the primary aggravating factor. On a downhill that steep the rear brake is close to useless so it didn't matter that I had a second brake. I slid all the way back so that my abdomen was on the saddle to try to get some weight traction on the rear and also dragged my feet, but to little avail, so I abandoned bike by rolling into the ditch along the side of the road.

nashvillebill

"Safety Factor" or "Factor of Safety" is the term you are looking for.

In pure tension, even a thin 1.5 mm cable probably could stand 300 lbs of pull. Fatigue though could be a real problem, and that is possibly why the cable in question broke. Maybe the outer housing was kinked there, or the end couldn't swivel and it was bending the cable too sharply. Maybe there was a stress riser from a nick at that point.

Vintage Raleigh

As a kid I only used to replace brake cables when they broke / snapped / frayed. Tyres were replaced when the tube was poking through the tread and even then I could get a few more miles with an electrical tape patch. Brake shoes when the housing was the primary braking surface.

avhed

Here is one for both styles of ends aimed at the BMX market for 30 years. Sold only with teflon lined housing in black & 65" only:
:

Odyssey Slic – Kable – 1.8mm – Cable/Housing – Black

Classtime 

Some of these guys are still here!

oneclick 

A quick click from that search engine leads to a table of wire-rope strengths.
It ends at 1/4", but looking at the min breaking strength values seems to show a consistent 1/4 ratio as the diameter is halved:
2" - 320000
1" - 83600
1/2" - 21400
1/4" - 5480
taking that a step further
1/8" - 1370
a step after that gets you to
1/16" (1.5875mm) - 342.5 lbs

Now, the rope was described as "Bright wire, uncoated, fiber core (FC) wire rope, improved plow steel (IPS)", and the steel used (and lack of core) in cycle cables could well improve on that figure.

Andrew_G

A few notes:

1) I's Bicycle / Cycles Grand Bois in Japan stocks new construction Campy reproduction brake cable sets, in black casing only. I've run the GB web page thru the Google translator:
https://cyclesgrandbois-com.translat...n&_x_tr_pto=sc

2) The Japanese cable manufacturer Nissen makes brake wires which are slightly thicker: 31 strands instead of 19. Also from Grand Bois:
https://cyclesgrandbois-com.translat...n&_x_tr_pto=sc

I do not know of a USA importer or distributor for the preceding.

3) Yellow Jersey in Arlington, Wisconsin has some good thicker brake cable choices. I'm currently using the thicker 1.8mm "Z Milano" cables from YJ on my vintage bike; the casing choices are black or gray. The supplied casing ferrules are a bit too small in outer diameter to fit snugly in Campy Nuovo Record brake levers; this sizing discrepancy caused the casing to flop down where the casing enters the brake lever body. So, I then had some custom stainless ferrules made from a machinist friend. The custom stainless steel ferrules provide a much better fit into the brake lever body, but they weren't cheap; I recall that they cost me $10 each. "A good craftsman's time costs money."

4) Jagwire (Taiwan) makes compressionless brake cable housing, which is supposed to firm up the brake feel: https://jagwire.com/products/housing...-brake-housing

5) Campagnolo recommends changing out brake and gear cables and the associated casings on an annual basis. See the attached maintenance schedule from Campy (below, the last entry).




Andrew G.

avhed

Does the extra .1 mm in the DuraAce increase friction near the aero lever?

dddd

Smaller diameter cables are more flexible in bending, so may actually last longer when, for example, a cable housing enters the frame near to the head tube, where a lot of handlebar motion may get forced into the cable and housing. I've seen rear brake cable failures at that exact location, hidden from view until they suddenly let go.

As well, the actual weight-per-length (and thus tensile strength and elasticity) of the cable may be similar between 1.8mm cables (having round strands) and 1.6mm "die drawn" cables (where the strands give up their roundness so as to be compressed closer together. A die-drawn cable can have higher density in other words.

davester

Couldn't tell ya. I don't have aero levers.

markk900

Good thing I don't have any Campy - cables get changed when they are failing (fraying) or get kinked/damaged.....but for me never on a "time basis". Its like in the outboard world where the plastic gas tank is supposed to be replaced every 2 years.....I believe I am going on 35 on a couple of mine.