Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

User Tag List

Reply
 
Thread Tools Search this Thread
Old 03-31-12, 05:39 PM   #1
LeicaLad 
Senior Member
Thread Starter
 
Join Date: Jun 2010
Location: Work in Asia, now based in Vienna, VA
Bikes:
Posts: 1,633
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
brake housing for derailleur cable?

Another one of those questions:

I know one should definitely not use derailleur housing for brake cables, but is there any reason not to use brake cable housing for derailleur cables?

I'm talking Jagwire Hyper quality housing.

I had enough left over, and it means matching cables and saving $. Yes? No?

Thank you.
__________________
1959 Hilton Wrigley Connoisseur (still my favorite!)
1963 Hetchins Mountain King (the gravel grinder)
1971 Gitane Tour de France (The War Horse)
1971 Gitane Super Corsa (The Garage Queen)
1980 Ritchey Touring (The Grail Bike)
1984 Tom Ritchey Team Competition (NOS show bike)
(replacing the stolen 1981 Tom Ritchey Everest custom)
LeicaLad is offline   Reply With Quote
Old 03-31-12, 05:48 PM   #2
Stealthammer
Still spinnin'.....
 
Stealthammer's Avatar
 
Join Date: May 2009
Location: Whitestown, IN
Bikes: Fisher Opie freeride/urban assault MTB, Redline Monocog 29er MTB, Serrota T-Max Commuter, Klein Rascal SS, Salsa Campion Road bike, Pake Rum Runner FG/SS Road bike, Cannondale Synapse Road bike, Santana Arriva Road Tandem, and others....
Posts: 1,208
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Derailleur cable housing needs to be as compressionless as possible for indexing, and most of it has linear windings rather than spiral windings to reduce the compression.

Also, the inner brake cables are generally larger in diameter than inner derailleur cables and would likely get stuck or drag within the derailleur cable housing, and derailleur cables being smaller in diameter could move around too much within brake cable housing for accurate indexing. Jagwire makes both brake cable and derailleur cable sets.


EDIT: Also, because the two cable housings are different outer diameters, the end ferrules from the brake cables housing may not fit properly into the shifters or rear derailleur.

Last edited by Stealthammer; 03-31-12 at 07:41 PM.
Stealthammer is offline   Reply With Quote
Old 03-31-12, 06:00 PM   #3
FBinNY 
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Posts: 29,428
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 95 Post(s)
There's a difference in how brake and index housing flexes.

Despite the irony of the name, top end brake housing is more compressionless than index housing. But when flexed the section at the inside of the curve can't compress, but the area to the outside is free to expand (imaging a flexed slinky to see what I'm describing). That means that imaginary line down the middle lengthens, and will change the trim of a derailleur as the housing flexes.

With index housing, the compression at the inside of a curve equals the elongation at the outside, so the neutral axis (the imaginary line that doesn't change) is right down the middle and so flexing won't change trim.

That's the logic for long spiral index housing. As to the reality, there really isn't really that much housing movement during normal riding, and I'm not sure that cable flex is an issue either way. The Jag brake housing you're using is relatively stiff and will probably serve fine for index housing, though you'll need to remember to keep the bars fairly straight when you adjust trim.

Go ahead and give it a shot, but don't cut the inner too close or crimp the tip too tight in case it turns out not to be OK after all.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is offline   Reply With Quote
Old 03-31-12, 06:17 PM   #4
LeicaLad 
Senior Member
Thread Starter
 
Join Date: Jun 2010
Location: Work in Asia, now based in Vienna, VA
Bikes:
Posts: 1,633
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks, guys. Thoughtful and informative, as always. (genuflect icon goes here)

This is for friction shifting with Suntour barcons and a wide touring rear end. I've done a brief shake down, and it seems to be good. Still, before I commit the the bar tape I'll see if my LBS has a length of derailleur housing to match. Might as well do it right.

Thanks, again.

__________________
1959 Hilton Wrigley Connoisseur (still my favorite!)
1963 Hetchins Mountain King (the gravel grinder)
1971 Gitane Tour de France (The War Horse)
1971 Gitane Super Corsa (The Garage Queen)
1980 Ritchey Touring (The Grail Bike)
1984 Tom Ritchey Team Competition (NOS show bike)
(replacing the stolen 1981 Tom Ritchey Everest custom)
LeicaLad is offline   Reply With Quote
Old 03-31-12, 06:42 PM   #5
FBinNY 
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Posts: 29,428
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 95 Post(s)
If it's friction shifting, you won't have any problem at all, go ahead and tape the bars and enjoy the bike.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is offline   Reply With Quote
Old 03-31-12, 07:57 PM   #6
LeicaLad 
Senior Member
Thread Starter
 
Join Date: Jun 2010
Location: Work in Asia, now based in Vienna, VA
Bikes:
Posts: 1,633
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Oh, great. Thanks, yet again.

I'm ready to finally wrap and ride.

Cheers!
__________________
1959 Hilton Wrigley Connoisseur (still my favorite!)
1963 Hetchins Mountain King (the gravel grinder)
1971 Gitane Tour de France (The War Horse)
1971 Gitane Super Corsa (The Garage Queen)
1980 Ritchey Touring (The Grail Bike)
1984 Tom Ritchey Team Competition (NOS show bike)
(replacing the stolen 1981 Tom Ritchey Everest custom)
LeicaLad is offline   Reply With Quote
Old 03-31-12, 08:29 PM   #7
Kimmo
bike whisperer
 
Kimmo's Avatar
 
Join Date: Dec 2009
Location: Melbourne, Oz
Bikes: copy/paste links: http://velospace.org/node/36949 http://velospace.org/node/47746 http://velospace.org/node/47747
Posts: 7,099
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by LeicaLad View Post
is there any reason not to use brake cable housing for derailleur cables?
It's not accurate enough for indexed systems >7spd. Might even give you trouble on that 5mm spacing, depending on the cable pull of the system you're using.

Quote:
Originally Posted by LeicaLad View Post
This is for friction shifting
In that case, not a problem.
Kimmo is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 05:56 PM.