Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

Rear Derailleur HOusing Loops.

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.

Rear Derailleur HOusing Loops.

Old 06-12-05, 06:19 PM
Thread Starter
Join Date: Sep 2003
Location: Home alone
Posts: 6,020

Bikes: Trek 4300 X 2. Trek 1000, Trek 6000

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Rear Derailleur HOusing Loops.

Look at this image from Park tool. How many new bikes do you see with a huge loop on the rear derailleur that is that long? I'm not trying to argue one way or the other, i have just noticed that almost every bike i've seen on the showroom floor has short loops.

Portis is offline  
Old 06-12-05, 10:18 PM
Retro Grouch 
Senior Member
Retro Grouch's Avatar
Join Date: Feb 2004
Location: St Peters, Missouri
Posts: 29,298

Bikes: Catrike 559 I own some others but they don't get ridden very much.

Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quoted: 1160 Post(s)
Liked 31 Times in 23 Posts
It depends somewhat on the bike and I don't think that they've chosen the best example. Some full suspension mountain bikes shift poorly unless that cable housing loop is on the long side.
Retro Grouch is offline  
Old 06-12-05, 10:22 PM
Senior Member
Nessism's Avatar
Join Date: Jun 2004
Location: Torrance, CA
Posts: 2,725

Bikes: Homebuilt steel

Mentioned: 6 Post(s)
Tagged: 0 Thread(s)
Quoted: 140 Post(s)
Liked 9 Times in 9 Posts
A large loop is better for reduced friction. The "Good housing" photo is a bit extreeme though; the piece of housing that comes with Shimano shifters is not long enough to make a loop that large.
Nessism is offline  
Old 06-12-05, 11:02 PM
Senior Member
cheg's Avatar
Join Date: Sep 2004
Location: Seattle
Posts: 807

Bikes: 2008 Davidson Custom Titanium, Custom Seven Steel Tandem, 1981 Shogun Touring Bike, 1974 Raleigh International

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 3 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
This is better yet: Avid Rollamajig
cheg is offline  
Old 06-13-05, 03:48 AM
Macaws Rock!
michaelnel's Avatar
Join Date: May 2005
Location: San Francisco, CA
Posts: 1,513

Bikes: 2005 Soma Doublecross

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by cheg
This is better yet: Avid Rollamajig
I've used those in the past with great success on Shimano derailleurs. I'm using an Sram 9.0 on my current bike and it doesn't need one.

San Francisco, California
michaelnel is offline  
Old 06-13-05, 04:34 AM
la vache fantôme
phantomcow2's Avatar
Join Date: Aug 2004
Location: NH
Posts: 6,266
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
thats what i like about the sram derailleurs, it requires a piece of cable 1/3 shorter than hte shimano ones and is almost straight
phantomcow2 is offline  
Old 06-13-05, 06:35 AM
Shimano Certified
mtbikerinpa's Avatar
Join Date: Dec 2004
Location: PA
Posts: 1,840

Bikes: 92 Giant Sedona ATX Custom

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 37 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Most cheap/poorly assembled bikes will have excessive loops on all the cables. When I performance tune those I end up chopping almost 18 inches of extra housing. Shorter means stiffer, until it gets so short it kinks on the cable. That is one of the reasons for housing stops on frames. Less housing to spring or drag.
mtbikerinpa is offline  
Old 06-13-05, 06:50 AM
Michel Gagnon
Year-round cyclist
Join Date: Apr 2002
Location: Montréal (Québec)
Posts: 3,023
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I tend to agree with Sara (our aviation/bicycle mechanic). As for the length of the derailleur loop, it depends on the bicycle. The trailercycle works better with a long loop, but the others I have work better with a loop as short as possible.

I haven't tried the Rooamajig. Anyone has lived through a few winters with it?
Michel Gagnon is offline  
Old 06-13-05, 09:26 AM
Senior Member
Join Date: Jul 2004
Posts: 293
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I've not ridden a rollamajig through a winter, but I've been commuting with one for about 200 miles now, often through some pretty hairy weather, and certainly on raods with salt and tons fo crud. It has held up well (*knocks wood*).

I originally thought that it'd end up being a fairly useless gimmick. Not so - the reduction in shifting effort was dramatic.
Sloth is offline  
Related Topics
Thread Starter
Last Post
Classic & Vintage
03-06-13 11:55 PM
Classic & Vintage
10-23-08 11:44 PM
Double D
Road Cycling
02-05-08 07:41 AM
General Cycling Discussion
03-18-07 07:57 AM

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

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.