Go Back  Bike Forums > Bike Forums > Framebuilders
Reload this Page >

Repairing Bulged Steerer tube

Notices
Framebuilders Thinking about a custom frame? Lugged vs Fillet Brazed. Different Frame materials? Newvex or Pacenti Lugs? why get a custom Road, Mountain, or Track Frame? Got a question about framebuilding? Lets discuss framebuilding at it's finest.

Repairing Bulged Steerer tube

Old 03-29-21, 12:55 PM
  #1  
duanedr 
Senior Member
Thread Starter
 
Join Date: Aug 2012
Location: Seattle
Posts: 358
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 60 Post(s)
Liked 44 Times in 30 Posts
Repairing Bulged Steerer tube

Thought this might be interesting. I had to extract a stem from steerer on an early 80's Columbine. The prior owner buggered up the Campy SR headset obviously not knowing what they were doing. Well, I did what you all would do to extract a stuck stem and after a few whacks it came loose. Since the HS was loosened, I thought I'd clean it out and re-grease and adjust it. As I had the fork out, I noticed a bulge where the wedge would have been. It took me about an hour to get down to a bulge of around .004-.005" and I felt like that was close enough - until I didn't. I took another run at it and it's now within a few thou variance like the rest of the tube. The HJ crown was also drilled off center as you can see in the 3rd photo. I'm sure this was done to take an internal/modern brake nut. I'll chuck this up in the mill and enlarge it and then make a shim that sits in there straight. There are other issues....

Initial measurement:
Fixing a bulged steerer tube. by Duane Draper, on Flickr

You can see how my blocks took a bit of a beating as I rotated the fork and clamped down on the bulge.
Fixing a bulged steerer tube. by Duane Draper, on Flickr

Showing it who is boss. The wood was so soft, it didn't damage the paint around the crown.
Fixing a bulged steerer tube. by Duane Draper, on Flickr
__________________
https://www.flickr.com/photos/54319503@N05/
https://www.draper-cycles.com
duanedr is offline  
Likes For duanedr:
Old 03-29-21, 03:33 PM
  #2  
unterhausen
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 21,606
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 1,328 Times in 962 Posts
Duane, when you made the tube bender I see on your flickr, did you turn the die too?
unterhausen is offline  
Old 03-29-21, 09:51 PM
  #3  
duanedr 
Senior Member
Thread Starter
 
Join Date: Aug 2012
Location: Seattle
Posts: 358
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 60 Post(s)
Liked 44 Times in 30 Posts
Yes. It's for a 7/16" tube for curved bridges. I have a round carbide insert tool that is just slightly smaller than 7/16" so I had to sort go in from the right, then the left and then back to the right and then compare to the tube and make further cuts from there. It wasn't too bad. I happened to have picked up a few 2"-3" rounds that were nearly perfectly .500" thick with 1/2'' hole. The handle part needs some work. The follower slips and doesn't follow the curve well which causes the tube to kink.
__________________
https://www.flickr.com/photos/54319503@N05/
https://www.draper-cycles.com
duanedr is offline  
Old 03-29-21, 10:19 PM
  #4  
unterhausen
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 21,606
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 1,328 Times in 962 Posts
That's too bad about the follower. I want to make a King Cage style bender that has multiple dies so I can make a rack more easily. There are programs that will tell you how to move a lathe tool to follow a curve like the one needed for a die, but I haven't tried any of them yet.

But thinking about it, King Cages have bends that are a little squished in places.
unterhausen is offline  
Old 03-30-21, 12:56 AM
  #5  
duanedr 
Senior Member
Thread Starter
 
Join Date: Aug 2012
Location: Seattle
Posts: 358
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 60 Post(s)
Liked 44 Times in 30 Posts
Originally Posted by unterhausen View Post
That's too bad about the follower. I want to make a King Cage style bender that has multiple dies so I can make a rack more easily. There are programs that will tell you how to move a lathe tool to follow a curve like the one needed for a die, but I haven't tried any of them yet.

But thinking about it, King Cages have bends that are a little squished in places.
Yes, I have a large (12"x12"x1") plate of stainless that has a bar across the bottom and I clamp the bar in the vice and it makes a nice work table for brazing small bits. I have holes in it where I mount my fork blade bender and small 1T arbor press. The goal is to make a small Diacro-like bender for racks, curved bridges and other small bits. Once I get the follower figured out, i think it'll work really well.
__________________
https://www.flickr.com/photos/54319503@N05/
https://www.draper-cycles.com
duanedr is offline  

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 - Do Not Sell My Personal Information -

Copyright 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.