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

Head tube internal step

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.

Head tube internal step

Old 06-18-20, 01:35 AM
  #1  
olioli
Junior Member
Thread Starter
 
Join Date: Jun 2020
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Head tube internal step

Is there a mechanical reason for the internal step at each end of a headtube , or is it just a means to using narrow thicker walled tube ? Can I just use straight tube?
olioli is offline  
Old 06-18-20, 06:05 AM
  #2  
unterhausen
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 23,147
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 2,717 Times in 1,891 Posts
The frame is built and then the headtube is reamed to the correct dimension for the headset. The step is the end of where the tube was reamed, and it's not important. Not sure how you plan to avoid it though.
unterhausen is offline  
Old 06-18-20, 06:39 AM
  #3  
olioli
Junior Member
Thread Starter
 
Join Date: Jun 2020
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Hi , apologies I should have been clearer...I'm looking for parts to build into a wooden bike frame , and the ones I've seen online (ie Bear Frame Supplies) have a step already cut into them. I was just wondering if it was possible to use unstepped tube of the right dimension , and not need to ream it since there would be no heat being used that might distort it.
olioli is offline  
Old 06-18-20, 07:25 AM
  #4  
Canaboo
Full Member
 
Join Date: Dec 2009
Posts: 478
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 41 Post(s)
Likes: 0
Liked 9 Times in 9 Posts
The problem is that tubing is basically not available in that interior dimension.
Canaboo is offline  
Old 06-18-20, 07:45 AM
  #5  
Nessism
Senior Member
 
Nessism's Avatar
 
Join Date: Jun 2004
Location: Torrance, CA
Posts: 3,042

Bikes: Homebuilt steel

Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 1981 Post(s)
Liked 388 Times in 307 Posts
Originally Posted by Canaboo View Post
The problem is that tubing is basically not available in that interior dimension.
...and even if there was the tube may not be perfectly round.
Nessism is offline  
Old 06-18-20, 07:49 AM
  #6  
wsteve464
Senior Member
 
Join Date: Jul 2016
Posts: 561
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 161 Post(s)
Liked 71 Times in 62 Posts
If you are talking about standard straight tubing specifically for head tubes you will need to ream it as they are slightly undersize to allow for distortion when brazing. Buy your headset and take it and the tubing to a machine shop. A bike shop maybe have the reamer but not the equipment to hold just the tube.

There are a couple of bamboo bike builders on here perhaps they will chime in.

Too slow
wsteve464 is offline  
Old 06-18-20, 11:13 AM
  #7  
guy153
Senior Member
 
Join Date: Dec 2019
Posts: 846
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 294 Post(s)
Liked 222 Times in 181 Posts
Originally Posted by olioli View Post
Hi , apologies I should have been clearer...I'm looking for parts to build into a wooden bike frame , and the ones I've seen online (ie Bear Frame Supplies) have a step already cut into them. I was just wondering if it was possible to use unstepped tube of the right dimension , and not need to ream it since there would be no heat being used that might distort it.
On the last frame but one I built I used a Reynolds 631 headtube with a 34mm ID for the usual 11/8 headset. It was supplied at the exact right size and didn't really need reaming. I sort of skimmed it a bit but hardly removed any material. I was a bit surprised by this as the Columbus HTs are deliberately a little small on the ID so you ream. But it seemed to work out absolutely fine.

It's just a plain gauge tube with no steps so you could use one of those.
guy153 is offline  
Likes For guy153:
Old 06-18-20, 01:12 PM
  #8  
unterhausen
Randomhead
 
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 23,147
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 2,717 Times in 1,891 Posts
I don't know how I feel about having the head tube be actual size. Haven't built a filleted frame in a long time, but last time I did filleted something together I got more distortion that I was happy with.
unterhausen is offline  
Old 06-18-20, 01:46 PM
  #9  
guy153
Senior Member
 
Join Date: Dec 2019
Posts: 846
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 294 Post(s)
Liked 222 Times in 181 Posts
Originally Posted by unterhausen View Post
I don't know how I feel about having the head tube be actual size. Haven't built a filleted frame in a long time, but last time I did filleted something together I got more distortion that I was happy with.
I was welding it and it did go a little bit oval but still averaged out to the right size and the cups went in fine. I was quite pleased because I only have a proper reamer for EC30 and was planning on seeing how I got on with a janky adjustable reamer (actually made in India surprisingly not China).
guy153 is offline  
Likes For guy153:

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 or Share My Personal Information -

Copyright © 2023 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.