Head tube internal step
#1
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?
#2
Randomhead
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 24,396
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 3,696 Times
in
2,517 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.
#3
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.
#6
Senior Member
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
There are a couple of bamboo bike builders on here perhaps they will chime in.
Too slow
#7
Senior Member
Join Date: Dec 2019
Posts: 955
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 321 Post(s)
Liked 263 Times
in
212 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.
It's just a plain gauge tube with no steps so you could use one of those.
Likes For guy153:
#8
Randomhead
Join Date: Aug 2008
Location: Happy Valley, Pennsylvania
Posts: 24,396
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Liked 3,696 Times
in
2,517 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.
#9
Senior Member
Join Date: Dec 2019
Posts: 955
Mentioned: 3 Post(s)
Tagged: 0 Thread(s)
Quoted: 321 Post(s)
Liked 263 Times
in
212 Posts
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).
Likes For guy153: