GT Derailer Cable Failure

[Baby Shoes]

The rear derailer cable on my GT Force 1 MB has now broken for the fourth time.Has anyone else had the same problem? My bike is less than a year old.

[Johan Bornman]

Where did it break? Under what circumstances?

No bike will have such an inherent flaw that makes the derailer cable break. If this were true, the gears won't shift.

Therefore something else is wrong. Post a photo.

[Baby Shoes]

The cable frays at the clamping mechanism.The distance between the fixed point of the cable and the clamping section appears to be too short,creating a bending movement on the cable.I have not noted that it breaks under any specific circumstance.

[Johan Bornman]

We need even more information to picture your problem. Does it break off at the anchor bolt, one strand at a time? Or does it break off somewhere between the anchor bolt and where it comes out the cable/barrel adjuster.

 

That gap is not user-adjustable and is a pre-set function of the derailer. Your cable is breaking, most likely, 'cause the anchor bolt is too tight.

 

 

[Baby Shoes]

It breaks at the anchor bolt one strand at a time.If I loosen the anchor bolt,will the cable not slip?

[Johan Bornman]

The anchor bolt needn't be as tight as some people make it. For instance, there is no need to tighten it until the cable is squashed flat. I think your problem is one of excessive force.

[leet22]

My scott does the same. Replaced the cable 2 weeks ago and is fraying again. Will replace and not tighten as much this time.

[techguy]

I agree with JB its a fitment error...

[Baby Shoes]

Thank you for the advise - I will try your suggestion and report back on the outcome.

[SURFER]

Had the same with my Scott

[Try try Tri]

Did anyone have better results with a not so tight bolt. Have a Scott and changing cables monthly.

[Skinnyone]

Ask yourself why is it happening? what is the common denominator? is it your LBS changing the cable every time - if so is it their way of making money out of your wash and lube? Is the cable snagging/breaking in the same place? if so why? 

 

then you may come up with a solution to the problem....as mentioned above there cannot (or very highly unlikely) be an inherent fault with your bike or the manufacture thereof to cause the issue...

[BaGearA]

check the bolt very carefully most of the time there is a slot in the plate where the cable needs to sit , its very rare that the cable should just be clamped between two flat plates

[David Marshall]

Your cables only need to be tightened to 4 or 5 nm.  Use a pre set 5 or torque wrench.  That said the new 11 speed Shimano road FD cables need to be 7 nm - and pulled tight tight! Not nice to set up.

[Ampandy]

Check the cable routing at the anchor bolt. If possible route it the other way around the bolt. Could be shearing off because of wrong routing.