# Rear derailleur cable housing length?



## evil lincoln (Jul 3, 2009)

How long should the last section of cable housing for the rear derailleur be? I'm not looking for a specific length, just a general guideline. I'm thinking it should at least be long enough so that the cable runs straight from the indexer to the cable lock...am I right about that? Thanks


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## KevinB (Oct 5, 2004)

See http://sheldonbrown.com/cables.html#routing


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## evil lincoln (Jul 3, 2009)

KevinB said:


> See http://sheldonbrown.com/cables.html#routing


I read that earlier today and didn't see anything specific to my issue, but I would say that number III is what you would follow for that. I just didn't want to make a large hoop that would end up getting tangled up in everything! I think I can probably work it out though.


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## KevinB (Oct 5, 2004)

evil lincoln said:


> I read that earlier today and didn't see anything specific to my issue, but I would say that number III is what you would follow for that. I just didn't want to make a large hoop that would end up getting tangled up in everything! I think I can probably work it out though.


Rule number II is also applicable here:

_No wrong direction bends (For example: as the rear brake cable leaves the top tube and makes the bend down toward the caliper, it should make a smooth transition from parallel to the top tube to parallel to the seat stays. If the cable bends up from the top tube before bending down toward the seat stays, it is probably too long. If the cable curves out past the caliper, then bends back at an angle more vertical than the seat stays, it is certainly too long._​
For the rear derailleur, the housing leaves the cable stop and loops down to the derailleur. If you make the loop so long that it is forced to bend upwards, or away from the derailleur, then you've made it too long. Otherwise, you should make the largest possible loop that doesn't violate rule II.


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## evil lincoln (Jul 3, 2009)

That makes sense to me. I'll work on it this evening.


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## shopcat_cycles (Dec 28, 2007)

Check the photos about halfway down the page. I found those to be helpful. You don't want too sharp of an angle leaving the barrel adjuster, as it will cause the ferrule to crack prematurely which will lead to bad shifting. 
http://parktool.com/repair/readhowto.asp?id=116


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