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-   -   Shifter cable partially broken (https://www.bikeforums.net/bicycle-mechanics/1091787-shifter-cable-partially-broken.html)

puttster 12-15-16 06:06 PM

Shifter cable partially broken
 
1 Attachment(s)
On my brand new to me Trek 7500 I noticed the plastic ferrule that maybe screws into the bracket of the right hand (rear) shifter is broken. About 1/3 of the cable is broken/exposed but the rest seems to be secure. In taking the bike out around the block there was some clanking in shifting, I wonder if this broken part could be the problem or it is more likely my not understanding how to shift properly.

Is this a DIY fix job and if so, could I get some instructions here for fixing it?

Well, also, does it actualy need to be fixed, considering I only paid $110 for the bike and it might not get ridden all that far or that much, maybe I should just wait and see?

shelbyfv 12-15-16 06:15 PM

If some strands are broken, it will only get worse and is most likely to break while you are riding (duh.) Go here Repair Help Articles | Park Tool for replacement help.

puttster 12-15-16 07:03 PM

Thanks. Could not find the relevant information there, though.
Questions I have are like, are the strands broken or just exposed? where can I get a replacement part? will I need to cut the cable, will I need an adjustment afterwards? How do you get the bracket off? Probably old hat to some but for me, not so much!

clydeman 12-15-16 07:17 PM

Yes, the cable looks broken and the clunking could be due to impaired cable movement not actuating the derailleur fully while shifting.

As for replacing cables, look through Youtube, off the top of my head RJtheBikeGuy has alot of videos demonstrating bike maintenance and repairs.

bhchdh 12-15-16 07:17 PM


Originally Posted by puttster (Post 19253867)
Thanks. Could not find the relevant information there, though.
Questions I have are like, are the strands broken or just exposed? where can I get a replacement part? will I need to cut the cable, will I need an adjustment afterwards? How do you get the bracket off? Probably old hat to some but for me, not so much!

The Park Tool site is a good source for both repair and tool information. Home Page | Park Tool

shelbyfv 12-15-16 07:22 PM

The cable should exit straight from the shifter body. Your cable is bent 90 degrees and it appears strands are broken. You will have to determine that for yourself. You can buy a cable online or at a bike shop. You will need to cut it to length and will need to adjust the tension after you replace it. In all honesty, since you are unable to use the excellent Park Tool site to answer your questions, I have little hope that you can complete this repair. Take it to a bike shop. Lots of folks don't do their own repairs, for a variety of reasons.

puttster 12-15-16 07:44 PM


Originally Posted by shelbyfv (Post 19253891)
since you are unable to use the excellent Park Tool site to answer your questions, I have little hope that you can complete this repair.

What do you mean? Thx.

shelbyfv 12-15-16 07:49 PM


Originally Posted by puttster (Post 19253924)
What do you mean? Thx.

:crash:

dedhed 12-15-16 08:25 PM

The ferrule that fits over the cable sheath (outer housing) is broken. Being index shifting housing the cable reinforcement runs longitudinally (these are the strands you see in the photo) to prevent compression so the indexed shifting stays crisp. Brake housing is circular wound and compresses a bit when used. Cheaping out you could likely get by with a new ferrule but if it was me I'd do a complete recable job (brake & shifters, inners and outers) on the whole bike and be done with it. You can buy outer from the LBS by the foot and likely have them cut the lengths you need.


JanMM 12-15-16 08:37 PM

Agree that the cable can't be seen in the pic but if some strands are broken it should be replaced. Plus the ferrule, which should cover the end of the housing including the reinforcement. Ideally, housing should also be replaced. The ferrule does not screw into the shifter.

dedhed 12-15-16 08:41 PM

Cutting and Sizing Cable Housing | Park Tool

http://www.sheldonbrown.com/cables.html

puttster 12-15-16 09:14 PM

So the exposed strands are not the actual cable but part of the reinforcement inside the black plastic tube? So is the black tube broken or is potentially nothing broken except the plastic ferrule?

That would be good news but where can you get a new ferrule? Or would a roll pin work? And obtaining one, is the only way to thread the cable through it via detaching the cable from the derailer?
Pls forgive my incorrect terminology, if possible.

xenologer 12-15-16 09:25 PM

>>looks at photo

Yeah, your shifter housing has burst out of it's ferrule, You'll need to recut and recap that. Otherwise the housing will just continue to unravel and you lose shifting ability alltogether.
Prefferably recap with an aluminum or brass ferrule instead of another plastic one. (plastic ones eventually all fail just like yours did)

Also would be a good idea to replace the shifter inner cable at the same time, as it's probably been kinked by that 90degree bend your housing is making.

on second thought, just take it to a LBS (repair shop) the job is too likely to mess up if it's a first time thing for you.

puttster 12-15-16 09:48 PM

I looked at the other end of the cable and it looks frayed pretty much like the front end! Or as Dedhed showed me, the sheath is frayed, either way, looks like bad news..
Also I noticed on the left side shifter when running the small gear if you try the shift up to the middle gear the chain won't go. You have to shift up to the big gear and then back down. Well, unless you nudge the grip half way forward, then it will shift from small to middle.

Maybe I do need a professional. What will it cost?

xenologer 12-15-16 10:09 PM

about 20$ labor and 5-10$ parts
for one shifter

double it if you need to do both of them (front as well as rear)

Andrew R Stewart 12-15-16 10:42 PM

One way this can happen is if the cables are pulled/bent beyond the ability of the end caps to remain structurally intact. A large and forceful swing of the bars or a significant pressure against the casing close to it's end (cap) can both cause this. Andy.

cny-bikeman 12-16-16 06:49 AM

The problem is not with the cable- it's not "broken" - but rather the ferrule on the housing, as others have mentioned. The cable housing is built with individual wires, and the ferrule is not stopping the ends from poking through the exit hole for the cable. Replace with a new ferrule, make sure the end of the housing is cut at 90 degrees (dremel/rotary tool and cutting wheel works great). Also make sure that the front housing section has been sized so as to allow the bars to swing all the way without straining the housing. You should also check the cable, as it may have become kinked. If you can't straighten it out so that it's fairly smooth again just replace it.

JohnDThompson 12-16-16 08:13 AM


Originally Posted by puttster (Post 19254062)
So the exposed strands are not the actual cable but part of the reinforcement inside the black plastic tube? So is the black tube broken or is potentially nothing broken except the plastic ferrule?

The exposed strands are from the compressionless housing, not the cable itself, but are nonetheless essential for reliable indexed shifting. The ferrule may be intact (hard to tell from the picture), and you may simply need to fix the housing. Unclamp the cable from the derailleur and slide the housing off the cable. Use a good cable cutter to trim the damaged end of the housing, file or grind the end of the housing so its evenly perpendicular to the axis of the housing, fit a new end cap, insert the cable and slide the housing back on until it seats in the ferrule. Re-connect the cable to the derailleur and adjust cable tension to achieve proper shifting.

cyccommute 12-16-16 08:41 AM


Originally Posted by cny-bikeman (Post 19254375)
The problem is not with the cable- it's not "broken" - but rather the ferrule on the housing, as others have mentioned. The cable housing is built with individual wires, and the ferrule is not stopping the ends from poking through the exit hole for the cable. Replace with a new ferrule, make sure the end of the housing is cut at 90 degrees (dremel/rotary tool and cutting wheel works great). Also make sure that the front housing section has been sized so as to allow the bars to swing all the way without straining the housing. You should also check the cable, as it may have become kinked. If you can't straighten it out so that it's fairly smooth again just replace it.

You are correct (unlike most everyone else) that the cable itself isn't broken. Only the plastic ferrule is broken. I see this all the time at my local co-op. It usually happens when the cable is too tight or the bend out of the shifter is too tight.

One mistake that everyone is making is that a the end of the cable is "frayed". This is something that manufacturers do to the ends of cables on nearly every new bike I see. For some reason, they think that the cable housing sheath has to be cut back so that the ferrule can fit on the cable housing. It's an unnecessary step and can actually make the shifting worse because of the way that the strands in the housing can clamp down on the inner cable. Here's an OEM cable housing with the sheath trimmed back

http://i144.photobucket.com/albums/r...psace37fd0.jpg

Compare the above to a cable where the sheath broke free from the inner strands and is actually broken. It looks similar but the cable was blunt cut when I installed it.

http://i144.photobucket.com/albums/r...s0gld2wtt.jpeg


Originally Posted by puttster (Post 19254111)
I looked at the other end of the cable and it looks frayed pretty much like the front end! Or as Dedhed showed me, the sheath is frayed, either way, looks like bad news..
Also I noticed on the left side shifter when running the small gear if you try the shift up to the middle gear the chain won't go. You have to shift up to the big gear and then back down. Well, unless you nudge the grip half way forward, then it will shift from small to middle.

Maybe I do need a professional. What will it cost?

As above, I doubt the sheath is "frayed". It was cut that way. The good news is that you can get away without replacing the cable housing. You should be able to just disconnect the cable from the derailer, pull the inner cable out, fit a new ferrule onto the cable and reinstall the inner cable. Just adjust the tension on the cable after installation and leave the limit screws alone! You should be good to go.

One caveat: Whether or not you'll need to replace the inner cable depends on the state of the cable. If it is frayed at all, you should either trim the frayed bit and get a smooth cable or just get a new inner cable. If you are using the old cable be careful how you insert it. If you twist it clockwise as you insert it into the housing you can often avoid fraying the cable.

This isn't a difficult fix. Good luck.

wphamilton 12-16-16 09:08 AM

Probably want the housing to be a little longer.

puttster 12-16-16 11:51 PM

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What a great forum. I called my LBS, Houston Bicycle, and the owner was not busy and said he'd replace two cables for $35. That was too good to resist. As it turned out only one shifter cable needed replacing but the rear brake handle was soft so he replaced that. It was a learning experience and as much as I appreciate the encouragement here for DIY, I am glad I did not make my own attempt until at least I saw what was involved.

After that he tightened up several other parts, filled the tires and put on a kickstand for $10 more. All in all, a super experience.

tablerone 12-17-16 02:58 AM

It is good to support LBS for their skills and knowledge.
Glad it fixed your bike and saved you some troubles.

fietsbob 12-17-16 12:24 PM

For low Compression shifter housing the Specialty cutter must cut through all the wires with out distorting the housing out of round.

For DIY you need to make a Tool Investment..

shelbyfv 12-17-16 01:10 PM

Congrats, this was the best solution for you, IMO.

puttster 12-18-16 11:36 AM

Testing the bike around the block I noticed on the left side shifter (of a 21 gear bike) when running the #1 small gear the chain won't shift up to the middle gear when you click the grip up into the #2 detent. To get the chain up you have to nudge the grip halfway to #3. Or you can shift all the way to #3 and then back down to #2.

Is this something I could take on myself?


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