seypat

What happens to the shifter cable/housing when the brake lever is squeezed? Do they move fore/aft with that action? Are they stationary? Does that cause additional stress for the cable?

cxwrench

Obviously nothing or you'd end up w/ your derailleur shifting every time you braked.The brake lever pivots separately from the shifter.

roadcrankr

Quote:
Originally Posted by cxwrench View Post
Because changing a $4.00 cable once year is such a huge ordeal, right?

Yeah, that change-out is way too frequent. Hopefully you eliminated all other culprits.
Mine works out to about a once-per-year chore. It's far less about the cost than the time.
Although, come to think of it, I replace my bar tape every other time. That stuff is expensive.
Cxwretch: please tell me where to find the $4 high-quality cables.
Imagine you get for dealer cost, so send me a batch and I will repay you.

cxwrench

After this you'll get nothing from me.

roadcrankr

Whoops. Typo. haha Well, give me some credit for not calling them brifters.
I hate when people call 'em that, too.
Seriously...where's these four buck cables you speak about?

BCDrums

No soup for you!

Andrew R Stewart 

QBP lists Jagwire Sport SS shift cables (CA4444) for less than $4 dealer cost, these would typically retail for $5-$10 shop dependent. I suspect cxwrench doesn't use coated cables, as I don't too. Andy

cxwrench

In that case we buy cables from QBP and our cost for SRAM is less than a buck when we buy a box. Shimano is a $1.50 so we sell both for $4.00/ea retail. Standard stainless steel cables. We sell Optislick for $8.00/ea. And this is in Marin County, so our labor prices are pretty high but we don't gouge people for product.

roadcrankr

Damn. My local shop sure sticks it to me. Part of our discrepancy here is that I always buy in pairs.
Still, that's like $18 a pair for regular Shimano, non-optislik. (Those never work right for me.)
Oh well....part of the price to pay to patronize the LBS. Along with CO2's, tubes, lubes, and other smalls. lol

JohnDThompson 

The Experimental Aircraft people have a rule-of-thumb that in order to prevent eventual fraying of a control cable, any pulley/guide/direction change on a cable should have a radius at least 50 times greater than the diameter of the cable. I can't see that fitting inside a modern shift lever, and I suspect that's why Shimano makes those routine replacement recommendations. At least, failure of a shift cable on a bicycle isn't likely to be as catastrophic as a control cable failure on an airplane.

cxwrench

They charge $9.00 each for standard Shimano Stainless cables?!? Are they pulling them out of a file box or are you buying individually packaged cables? Even then they shouldn't be that expensive. If your shop won't sell them for a reasonable price screw em and get them online.

Crankycrank

Update: Well, my Alligator cable started fraying at the shifter not long after this so roughly about 2/3 the mileage of the S or J brand cables. I've had the same bike, groupset, basically everything that isn't a wear item and those were replaced with like parts and also do the same roads in the same conditions all for the last 13 years so a pretty consistent conditions for testing cables. I had one more of these cables so will report back on that one when it wears out in case the first was a fluke. Can't recommend these after this experience.

FBinNY 

You may get varying life from various cables, but ALL cables will fray and break there because the problem is inherent in the design.

If you've ever bent a paper clip back and forth until it breaks you're familiar with the issue. As the cable winds onto and off the lever's curve, it's being bent and straightened. Eventually it will "work harden" and become brittle, after which strands will break over time. Folks who shift often between the same few gears are bending the cable in the same place and will see lower life than those who shift less often, or use a greater range of gears, but ALL cables will break this way over time.

smd4

Maybe so, but it’ll be a cold day in Hell before that happens with my downtube shifters.

Picked up some of the Alligator cables after reading about them here. They appear to be very high quality and super slick.

FBinNY 

Possibly, or at least a long time from now. But things have changed significantly between wen your levers were made and now. First of all, the makers of D/T levers weren't working with physical space constraints, and so had the freedom to use a larger radius on the pulley section. We also have to consider how modern index systems changed how we ride. BITD I was riding 10s (5x2) and the gear intervals were larger than they are today, that combined with friction shifting meant I would settle into a gear and not shift until I needed to. Nowadays with 10s or more and the convenience of in the lever index shifting, I shift all the time, constantly fine tuning my gear choice. I'd venture that modern riders are shifting at least 3x more often than before index.

Since cable life relates to shift count and not miles, that means we can expect less than 1/3rd the cable life if all other things remain equal. Factor the smaller pulley radius, and nobody should be surprised by short cable life.

FWIW, back in the bronze age I was using Campy bar cons with 7x7 wire rope cables. Riding 15k+ miles per year, I'd replace the cables every 2 years as preventative maintenance. No idea how long they might have lasted otherwise.

Lombard

Super slick won't make Shimano shifters chew cables less and they won't last any longer. The Alligator 31 cables may last longer because they have a more strands of thinner wires which flex easier. The theory is that they will take longer to fatigue because they are more flexible.

To be clear, I have had the same problem with Shimano shifters eating cables. Apparently the problem started in the 5700/6700/7900 generation when they started the under bar tape routing and the shifter wraps the cable very tightly inside the shifter. My 6800 road bike has internally routed cables which are a royal PITA to change. I was changing the rear shifter cable every 1500-2000 miles and even had one that only lasted for 800 miles. Finally at 10K miles, the rear shifter broke. I decided to switch to SRAM Force 22 shifters and derailleurs. The worst thing about SRAM is that the FD is tricky to set up correctly. Once I figured that out, it has shifted flawlessly.

roadcrankr

Good timing on this thread. I replaced my shabby bar tape and figured it a good time to replace the rear shifter cable.
DA 9000-series. 3k miles and the cable still looked fine. Swapped it out, nevertheless.
When those suckers go, they seem to deteriorate quickly. And usually around the 3k mark for me.
Oh, and for the first time ever for any generation DA STI, I got the cable perfectly set, without the need for adjustment!
No doubt, some of you hotshot wrenches routinely nail it.

JohnDThompson 

I've had individual strands break on downtube shift levers, but not the whole cable. Possibly because the broken strands prick my fingers when I shift gears, alerting me to the problem before complete failure occurs.

JohnDThompson 

I suspect it may actually shorten cable life, as the slick cables are die-drawn after winding to create a smooth surface for the coating. This work-hardens the strands before the cables are even installed and suffer the useage work hardening @FBinNY notes in message #38, above.

Lombard

I usually get a one ride warning. The first thing that happens is that shifting suffers as strands break and you can't shift into the largest cog. No matter how you try and adjust the cable, you can't get it to play nice. At this point, time to turn around and head back to the start site unless the ride is super flat. I have always managed to nurse the bike back home without losing all shifting.

Schweinhund

It's the only thing that makes any sense.

datlas 

The first sign I usually get is a little finicky going into the smallest 2 or 3 cogs. I believe this is due to the burr-like nature of the frayed cable which increases resistance. That seems to be the first clue. The inability to go to the largest cog usually happens JUST BEFORE the break.

Koyote

When mine fails, it's usually on a loop ride and when I'm furthest from home. So I've ridden back a few times with just two gears: 50-11 and 34-11. Good times in a very hilly area.

SoSmellyAir

On my bike, I have to remove the BB cable guide from the BB shell in order to thread a replacement RD shift cable through the BB cable guide. In order to remove the BB cable guide, I have to disconnect both shifter cables. Which means that I might as well replace both shift cables at the same time, every 18 months or so.

Lombard

I think is has more to do with when strands start breaking, the cable becomes effectively longer.