MikeR

I ride a Bianchi SanRemo with campy Mirage ergo power shifters. These shifters go through cables quickly, and the cable seems to fail at the most inopportune times. The cable breaks right where it attaches to the shifter. I think that it gets flexed a lot in that spot. Here are my questions:

Is there anything I can so to prolong the life of the cables?

Would it be worthwhile to replace the cables at the beginning of the riding season so I know that they will not leave me stranded in the middle of a ride? (I’m sure that they will last one season).

Is it difficult to thread new cables into the existing housing without taking off the bar tape?

In the case of a break, is there a friction shifter I can mount on my downtube as a spare? Which brand do you suggest?

There is a braze-on where the cable housing terminus is screwed to the downtube. Could I attach a downtube shifter there or should I get a clamp-on shifter? Again, what brand?

Thanks for your advice.

demoncyclist

I have a Mirage grouppo on my Bianchi. I have NEVER broken a shift cable. I replace them every couple of seasons. I can't think of a way to use a second shifter without carrying spare cable anyway, so you can either do that, or you can make sure that your cables and housing are in good shape to begin with. You can easily thread new cables into existing housing, but you need to make sure that the housing isn't the source of your troubles to begin with. Is the shifting smooth, or do you have to really push on the lever to cahnge gears? My thought is that there is a burr or a crushed spot right at the end of the housing, where the cable enters at the shifter. That would definitely stress the cable and eventually cause it to fail. Might be worth re-taping the bars to find out what is really going on inside there.

sydney

If you think you need a backup, carry a shifter,spare cable,and screwdriver to change things out. I've never had a cable break.

Retro Grouch 

Shouldn't somebody insert a smartalac Shimano vs. Campy comment here? There'd certainly be one by now it it were the other way around.

MikeR

Well I get about a season and a half, so I could replace at the beginning of the season. My rides are rolling hills and I do a lot of shifting.

It looks like they are breaking where the cable goes around the wheel that the shifter uses to pull the cable - it's about 1/4 inch (or less) from the cable end. The LBS says that this is where the cables are stressed the most because the shifter pulls the cable around a small wheel (or cog) and this is flexing the cable back and forth - eventually breaking it. It could be where the cable goes into the housing - I'll have to check that.

The way I discover it might tell you what's happening. When it is starting to go, I feel a wire sticking out of the side of the hood. When I peal back the hood cover I can see the wire ends sticking out between the cable housing and the spot where the cable attaches to the shifter. The wires are breaking one at a time like if you would flex a cable back and forth a lot.

MikeR

Well - I might if I keep breaking cables

roadfix

My 1993 Campy Ergo shifter cables are still original.

MikeR

Wow, which model? maybe the low end Mirage don't last as long - or maybe they make them cheaper now - my bike is a 2001.

roadfix

Record Ergos.....but I don't think that should make a diff...

Portis

Is it possible that you are having to exert an extra amount of force on the cable to complete shifting at any point? I used to break a lot of cables on my mountain bike until i figured out that the BB was too wide and cause me to really exert to get to the outermost position on the front derailleur.

I am no expert but i have had others tell me that cables aren't supposed to break very often. Some guys claim they have never broken a cable. I have never since i corrected the problem on my mountain bike about 1 yr ago.

MikeR

I have not noticed any extra effort - but this is my first REAL bike so I don't know how much to expect. I assume that BB = Bottom Bracket? This is stock equipment so I don't know how the BB could be too wide. How did you fix it - I thought the BB width is not changable.

KleinRider

I would check the end of the cable housing for any burring, or a slightly crushed end. I've never broken a cable and I have the originals on all of my bikes.

Oh, and BB is bottom bracket as you guessed.

Surferbruce

could it also be a bad outer housing?

Portis

I'm not asserting that the BB is the problem in your case. I am drawing the parallel because too much friction caused my cables to break. It could be the same deal in your case. IOW, there is either too much tension on the cable at the time it breaks or like someone else said, maybe their is a burr or something cutting the cable.

A cable in good condition in normal operation should not break.

seely

How are the angles of your cable housing? Nice smooth gradual curves or are they pulled too tightly?

Trekke

I have this happen on Shimano shifters also. Breaks at exactly the same point. My advice (for what it is worth): If you cannot identify what is causing the cable to break or a contributing factor that can be corrected then just replace the cable ever season as a regular maintenance item. Cables are very inexpensive. I pay about $2 for one. And they are really easy to install. I always mark the cable with a sharpie on the far side of the cable clamp and mark the new one the same length. That gets you real close then simple cable tension adjustments dials the shifting right in. No need to mess with limit screws. I would not carry a spare cable and tools unless I was doing a self supported brevet or other ride where there is no sag support.

MikeR

That's a good idea - I think that I'll look for the problem the next time the bar tape comes of, but until then (and if I don't find the problem) I'll put new shifter cables on my maintenance schedule and keep spares around just in case.

Portis

Problem is that a broken shifter cable can leave you with a mess in the middle of nowhere. Trust me on this one. It has happened to me.

MikeR

Fear of this happening is the reason I was thinking of getting a basic downtube friction shifter that I could carry just in case. Then if the cable breaks (it always breaks at the handlebars) I could cut of the extra length and rig up the friction shifter to get home. The only problem is I don't know enough about friction shifters to know which one to get. I don’t know if I can mount one on the screw slot that the cable guide is presently screwed to, or if I should get a clamp-on shifter. Anyone have any knowledge of friction shifters?

operator

Could be he's using the wrong type of cable for shifter. I continually broke the brake cable on my old beater bike until I realized I had the wrong type of cable in there (mtn head vs road head).

roadfix

No sense carrying around an extra shifter unless you're a cycle tourist miles from nowhere.
Instead, should your cable break in the middle of your ride, simply set your limit screw on your derailleur and ride home as a single-speed.

MikeR

Although that's possible - it's not probable. My LBS put them in and (so far) they have proven to be knowledgeable.

MikeR

Yep - did that last time, but it's no fun when you have 50 hilly miles to go. Plus the cable sems to break just before a big group ride that I've been looking forward to. With the friction shifter, I could do the group ride and do the fix after.

roadfix

Well, I guess you can always lug around the extra shifter with you..... it'll double as a tire iron....

MikeR

The only problem is I don't know what to get.