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

Need Sturmey Archer dynohub advice (it's stuck)

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.

Need Sturmey Archer dynohub advice (it's stuck)

Old 06-11-05, 11:50 AM
  #1  
itsbarry
Newbie
Thread Starter
 
Join Date: Jun 2005
Posts: 1
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Need Sturmey Archer dynohub advice (it's stuck)

Hello,

My dynohub doesn't spin very freely. They're supposed to rotate without serious binding, right?

I partially dismantled my Sturmey dynohub following instructions from sheldon brown and elsewhere. There was rust on the magnet when I opened it up. I understand if I separate the magnet from the armature I will essentially destroy the magnet.

Problem is, I think something underneath the armature is causing it to bind up, so I want to totally tear it down and inspect everything carefully. What exactly is a "keeper" and how do I use it to retain the power of the magnet?

Thanks in advance,

Barry
itsbarry is offline  
Old 06-11-05, 04:54 PM
  #2  
Sheldon Brown
Gone, but not forgotten
 
Sheldon Brown's Avatar
 
Join Date: Jul 2002
Location: Newtonville, Massachusetts
Posts: 2,301

Bikes: See: http://sheldonbrown.org/bicycles

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 12 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by itsbarry
Hello,

My dynohub doesn't spin very freely. They're supposed to rotate without serious binding, right?

I partially dismantled my Sturmey dynohub following instructions from sheldon brown and elsewhere. There was rust on the magnet when I opened it up. I understand if I separate the magnet from the armature I will essentially destroy the magnet.

Problem is, I think something underneath the armature is causing it to bind up, so I want to totally tear it down and inspect everything carefully. What exactly is a "keeper" and how do I use it to retain the power of the magnet?
The keeper is an iron hockey puck, the same size and shape as the armature. It's a basically useless tool nowdays, because it is only used to permit replacement of the armature, and armatures are no longer available.

You can remove the magnet and armature together for cleaning, adjustment and the like. It is normal for Dynohubs and other hub generators to feel "notchy" as they turn, that's the 20 pole magnet "snapping" into position. It usually feels very severe if you hold the axle in your hand and spin the wheel, but it's not a problem once it's actually on the bike.

Sheldon "Switched To Shimano Generator Hubs, Way Better" Brown
Code:
+---------------------------------------------------------------+
|  There are 10 kinds of people in this world:                  |
|  Those who understand the binary system, and those who don't  |
+---------------------------------------------------------------+
Sheldon Brown is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
clockwork247
Electric Bikes
3
04-10-12 10:02 AM
powitte
Bicycle Mechanics
0
05-28-11 09:11 PM
jcs1
Mountain Biking
1
06-30-10 05:58 PM
mrbertfixy
Track Cycling: Velodrome Racing and Training Area
0
04-22-05 11:32 PM
gravityhurts
Singlespeed & Fixed Gear
0
12-06-04 01:44 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.