Corroded thread on derailleur hanger
#1
Fork and spoon operator
Thread Starter
Join Date: Jun 2011
Location: Hopkins, Minnesota
Posts: 577
Bikes: 2013 Surly Crosscheck, 1990 Schwinn Impact, 1973 Schwinn Continental
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 37 Post(s)
Likes: 0
Liked 11 Times
in
7 Posts
Corroded thread on derailleur hanger
I took off my rear derailleur to clean it, and when I went to put it back on the threads were too damaged to get it back on. I've never had this happen before; anyone else? Can I get it re-tapped? Will it be as good as new? I'm nervous that it's been damaged by road salt, and lost metal. It's a nice steel bike that's only about three years old, but I've ridden it every day through Minnesota winters.
#2
Banned
you may be cross threading it and have damaged the threads ..
yea a bike shop should have taps to chase the threads and straighten them out
yea a bike shop should have taps to chase the threads and straighten them out
#3
Senior Member
#4
Senior Member
Join Date: Nov 2013
Location: Napa, California
Posts: 470
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 3 Times
in
1 Post
Did you apply grease to the bolt before attempting to reinstall? If not, always do that, especially if the threads were probably already a bit rough with corrosion. And like said above, most likely the threads just started to get a bit cross threaded and should be easily fixable by any competent bike shop.
#5
Senior Member
Join Date: Aug 2009
Location: Berkeley, CA
Posts: 7,244
Bikes: '72 Cilo Pacer, '72 Gitane Gran Tourisme, '72 Peugeot PX10, '73 Speedwell Ti, '74 Peugeot UE-8, '75 Peugeot PR-10L, '80 Colnago Super, '85 De Rosa Pro, '86 Look Equipe 753, '86 Look KG86, '89 Parkpre Team, '90 Parkpre Team MTB, '90 Merlin
Mentioned: 87 Post(s)
Tagged: 0 Thread(s)
Quoted: 834 Post(s)
Liked 2,126 Times
in
555 Posts
You can try to chase the threads by installing the derailleur mounting bolt from the back side of the hanger. It should thread all the way through and fix any damaged or crossed threads. Clean up the threads well, and apply liberal amounts of oil (cutting oil, ideally, but standard oil is better than nothing). Use a cheap spare derailleur mounting bolt if you have one.
#6
Full Member
Join Date: Dec 2011
Location: SE Michigan
Posts: 464
Bikes: Serotta CRL, Litespeed Blue Ridge, Bacchetta Ti Aero, Cannondale delta V, 67 Schwinn Sting Ray stick shift.
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 26 Post(s)
Likes: 0
Liked 7 Times
in
6 Posts
You can try to chase the threads by installing the derailleur mounting bolt from the back side of the hanger. It should thread all the way through and fix any damaged or crossed threads. Clean up the threads well, and apply liberal amounts of oil (cutting oil, ideally, but standard oil is better than nothing). Use a cheap spare derailleur mounting bolt if you have one.
Not removing any metal this way similar to a roll form tap, a superior tapping method in almost every circumstance.
Thread
Thread Starter
Forum
Replies
Last Post
dblA
Bicycle Mechanics
26
04-19-16 05:56 PM
wayback
Classic & Vintage
19
11-18-11 10:43 AM