Has anyone had a problem with the gear cable breaking on the Shimano XT M772 Rear Derailleur. I’ve got through a number of gear cables of different types where it always breaks at the derailleur by the cable clamp.
On closer inspection, when the cable is at its greatest tension, the angle of pull changes to bend the cable. This puts an extra strain on the cable causing it to break.
I’ve noticed that some other Shimano rear derailleur do the same thing. Is there a solution to this apart from getting a new derailleur?
Most people tend to have too short a loop of outer between their last cable stop and derailleur so lengthening this may help.
I know you said apart from getting a new derailleur but you should look at the "shadow" derailleurs as they have much cleaner cable routing with a less severe bend.
The loop for the outer is fine, I have a smooth generous curve.
The problem is where the cable is exposed for 2-3cm on the derailleur. It is pulled at one angle for the smaller gears, then as the tension increases the angle of pull sharpens. The cable therefore breaks near the clamp screw.
I've never seen this.
I would check your gear stops - many people set the bottom gear stop slightly too far out, meaning that in bottom gear there is a lot of unnecessary tension in the cable.
Yep, that's a lot of force to snap a gear cable - or is it gradually being worn & the strands are breaking one by one.
I've not seen anything like this before either.
It could be caused by you over-tightening the cable clamp which is causing the strands to break.
I found that putting a small sleeve over the bare cable where it meets the clamp extended the cable life a bit.
I'll try to take some photos to show you what is happening.
have you got the cable going into the grove (where its meant to go) and not the other side of the clamp bolt causing the cable to be at a funny angle