Bah Humbug

I did have a friend whose cable (front) shredded in such a way she was stuck on the big ring, not small. Even though it's supposed to not do that.

easyupbug 

A 6 year old Ultegra Di2 on a carbon frame came my way and I enjoy it. Don't get me wrong, as a mechanical engineer w/ years of maintenance background I love my mechanical transmissions. I need more practice getting the correct button which are directly adjacent but shifting is more precise than my finest tuned DA and Campy mechanicals and I enjoy that.

Redbullet

This tells me that you ride quite a lot!
I only have mechanical and I clean and lube the chain almost every 2 months - some 1300 - 1500 km. I change it at 10.000 km, although it still has lot of life remaining, maybe 25%, since it hardly reaches the first level on caliper. Cleaning the bike takes me less that 1 minute before every ride, so it does not count.
As about changing shifting cables - I did it after 30.000 km, although they had no issues. But they were old and I heard that most riders change them much often.

Redbullet

For me this is scary. If such thing really happens, then we should never ride a bike with cables. Because a brake cable takes exponentially bigger abuse than a shifting cable. If the brake cable breaks, we have all the chances to never come back home, either riding or walking...

Maelochs

I have removed the brakes from my bike to forestall potential brake failure.

Next I am taking off the tires ... a blowout could cause a fall.

tomato coupe

What are you doing about potential head injuries?

genejockey 

Well, you know helmets can't protect you from everything, so........

Maelochs

I am relying on the experience gained from past head injuries to help me survive both real and potential head injuries ... it is the virtual head injuries I might suffer on certain web sites which frighten me ... I always wear a helmet on BF.

mschwett 

the ignore function is the BF equivalent of a helmet.

ummed

I did have a brake cable break at the bottom of a steep (but not particularly long decent) where I regularly hit 50+ mph. Fortunately, it was just as I was about stopped anyway.

Kontact 

There may be a few modern bikes with full length internal cables that would be easy to replace. But the vast majority require the BB cable guide to be disassembled - undoing both front and rear derailleur wires - to fish them through and into the stay or seat tube exit.

Most internally routed bikes are terrible to work on.

Atlas Shrugged

Exactly that’s why I only ride hydraulic discs.

Kontact 

Right. Because brake cables are constantly breaking, and bike hydraulics never leak.

In 35 years, I have never seen a broken brake cable. Some have been so chewed up from straddle bolts that you would think they would break, but I've never seen nor heard of one outside of this thread.

But BF is a special place where reality need not apply.

GhostRider62

I guess I've been lucky. My internal cabled bikes have been a Kestral, Felt, Cervelo, and another POS. I could pull out the cable (not the housing) and slide another in like a hot knife cutting butter. I think my Trek might have been dodgy to run a cable. Don't know but I do know in 40-50 years, I have never broken a brake or shifter cable. I ride a lot.

Trakhak

I once had a front brake cable fail. The wires of the cable pulled out of the molded bead at the lever end. That was startling.

A good topic for a new "Bicycle Mechanics" thread: "I never saw that before." Like The GCN Show's popular "Bodge or Hack" segments.

I could start the thread with my jury-rigged triple front derailleur. A spring anchor point on the front derailleur of my Cannondale SM-500 commuter bike snapped off, and I didn't feel like spending a day hunting down an appropriate replacement derailleur at local bike shops. So I figured out how to tie the ends of a section of a cut-up inner tube onto the derailleur to replace the spring. Looked goofy but worked even more smoothly than the original configuration.

DaveSSS 

That's how my Colnago C-RS rim brake frames were. A real pain to route the cables internally, with a cable guide under the BB and no internal cable guides. That prompted me to switch from Campy Chorus 12 to SRAM AXS to eliminate the shift cables. I rode that setup for about a year.

That experience supported my change over to disc and wireless shifting. I bought two new Cinelli Superstar frames for $1000 each. The frames have an internal cable guide, so you shove the cable housing into the side of the down tube and it comes out the side of the chain stay. I used my SRAM AXS rim brake levers and Juin-Tech cable operated hydraulic calipers first, then switched to full hydro about a year later.

​​​​​​I've also built up two disc frames with full internal routing and integrated bar/stems. Routing hydraulic hoses through the bars wasn't difficult and routing the rear brake hose wasn't difficult either. There's a fairly large hole in the chain stay with a plastic grommet to fit a 5mm hose.

genejockey 

I was recabling my Canyon Endurace, and I THOUGHT it had full internal liners. I did the rear one first.It threaded fine, but i had a little difficulty fishing the end out at the back of the chainstay. Once I figured that out, I pulled it through, fed it through the housing loop and into the RD, pulled it taut, clamped it down, adjusted the tension for nice, crisp shifting. Then I cut off the excess cable and crimped on a cable end. Then I turned my attention to the front derailleur, where I expected the cable to feed through and come up the liner that comes out of the top of the BB and feeds to the FD, but it didn't. Hmmm.

I looked under the BB, and there's a little panel. I pulled it off, and it has sections of cable liner and routing built into it. So I fished out the FD cable, fed it through the liner, and it popped out right by the FD. Easy peasy.

Then I realized that the RD cable was NOT going through the liner. No, it was just stretched across the crank spindle. And I realized I'd made the same mistake as the guy who posted that his RD cable sawed its way through the spindle.

SO, I unclamped it, fed it through the liner properly, and set up the RD AGAIN, and had BARELY enough extra cable beyond the pinch bolt to crimp on a cable end. Lesson learned: DO NOT ASSUME YOU KNOW WHAT YOU'RE DOING!

Maelochs

My Worswells have that little hatch in the bottom. On the one hand it makes it easier to run the cables despite no inner liners .... on the other hand, it can still be a challenge.

I suppose I could do it roadside if it was early in a ride, i wasn't too tired, weather wasn't too anything--hot,cold,wet,windy,dark---and if I had extra patience that day.

SoSmellyAir

What is an internal liner? How is such a liner different from a bottom bracket cable guide? And how can a shift cable saw through a crank? Would the shift cable not wear out first?

On my Synapse, there is a panel under the bottom bracket shell. Popping it off reveals the shift cable guide. It is possible to thread cables through this guide without first removing the guide from the frame. So the last time I had to replace a snapped RD cable, I might as well replace the FD shift cable too. Maelochs This is not something I would attempt outside my garage.

ummed

I didn't have any trouble routing the cables in my (1st gen) Venge and CruX. But also, not routing cables at all is way easier

Edit: This also really helps

genejockey 

The internal liner is just like the inside liner in shift cable housing. In the case of the Canyon, they're both run through the cable guide on the inside of the BB hatch, The front ends of both are loose, and long enough to extend some way up the downtube. The cable guide holds them under the spindle, then the FD one exits the BB shell through a hole on top between the chainstays, and extends up to the FD. The RD one passes down the drive side chainstay all the way to the end, where there's a grommet/insert that the housing loop fits into.

The cable can saw through the crank spindle, especially an aluminum one. It happens, apparently.

merlinextraligh

this kind of ridiculous. First, brake cables are thicker and more robust than shifter cables for a reason. Second the system is redundant, you have two brakes, either of which will stop you before flailing into oblivion. Third, worst case scenario, you stop the bike with a foot on the front tire behind the forks.

my best estimate is that I’ve ridden about 200,000 miles, a good portion of those in the high alps, Colorado Rockies, Appalachian mountains and Sierra Nevadas. In that time, I’ve never had a cable break on a rim brake. Or have I heard of any teammate or acquaintance have such a failure.

Conversely, it’s not very difficult to boil hydraulic fluid to the point you hydraulic discs don’t work if you use bad technique.

to the extent your post wasn’t intended to be facetious, in which case I fell hook line and sinker, if not it’s way over the top fear mongering.

SoSmellyAir

Not to mention, the brake cable does not go through the same tight radius bend taken by the shifter cable within the STI lever.

GhostRider62

By my reckoning I have more that 200K miles and have never broken a single cable on a bike when riding. If the probability of failure on one brake cable is 1 in 1,000. The chance both break is 1 in a million. If it is 1 in 10,000 for one, the odds of both breaking at the same time is 1 in 100,000,000. I also replace cables on PM.

I have had RD break. I've had a rear dropout break. Cable? Nope.

Maelochs

I am pretty sure he was not being serious.

However,when I said I was removing the tires to prevent blowout i absolutely was.