Building a bicycle frame for the first time. Questions about head tube sizes.
#1
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Joined: Aug 2012
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Building a bicycle frame for the first time. Questions about head tube sizes.
First time builder and I tried looking in to the forum, but did not find exactly what I was looking for.
I am a mechanical engineer at University of Washington, and have access to the machine shop. Any suggestion or critique is welcome.
Here is what I have in mind so far:
Building a rode bike.
Frame : https://www.cycle-frames.com/bicycle-...CS-and-SS.html
Bottom Bracket : https://www.cycle-frames.com/bicycle-...PER-LIGHT.html
Steerer tube : 1 1/8"
Seat tube length: not sure
Drop out : not sure
Head tube size : not sure
Fork : not sure
lug-less
Frame geometry

1, On cycle-frames, they gave me a choice of 31.8 mm or 36 mm for head tube diameter, which one do I need to chose to fit a 1 1/8" steer tube. On the side note, is a 1 1/8' steer tube size a good size?
2, What is a common/good drop out fork type
3, Suggestion on forks would be awesome
4, What are some good sites that sell bike frame building material and frame building information.
Thank you for reading
I am a mechanical engineer at University of Washington, and have access to the machine shop. Any suggestion or critique is welcome.
Here is what I have in mind so far:
Building a rode bike.
Frame : https://www.cycle-frames.com/bicycle-...CS-and-SS.html
Bottom Bracket : https://www.cycle-frames.com/bicycle-...PER-LIGHT.html
Steerer tube : 1 1/8"
Seat tube length: not sure
Drop out : not sure
Head tube size : not sure
Fork : not sure
lug-less
Frame geometry
1, On cycle-frames, they gave me a choice of 31.8 mm or 36 mm for head tube diameter, which one do I need to chose to fit a 1 1/8" steer tube. On the side note, is a 1 1/8' steer tube size a good size?
2, What is a common/good drop out fork type
3, Suggestion on forks would be awesome
4, What are some good sites that sell bike frame building material and frame building information.
Thank you for reading
#2
Senior Member
Joined: Sep 2008
Posts: 1,350
Likes: 4
From: Collegeville, PA
Bikes: Ruckelshaus Randonneur, Specialized Allez (early 90's, steel), Ruckelshaus Path Bomber currently being built
You realize you've selected an off-road tubeset for a road bike, right?
Use 36mm head tube for a 28.6mm (1.125") steerer. It is the modern standard for most frames, though some builders still use 1" steerer/31.8mm head tube, usually so they can used threaded headset & quill stem (which I prefer)
For your first frame, use a socketed dropout. All you have to do with the stays is measure and cut them straight, which is easier than slotting.
Make your own forks? Otherwise, Wound Up or Enve
Suppliers: best known are Nova, Pacenti, and Henry James in the US and Ceeway in the UK.
Use 36mm head tube for a 28.6mm (1.125") steerer. It is the modern standard for most frames, though some builders still use 1" steerer/31.8mm head tube, usually so they can used threaded headset & quill stem (which I prefer)
For your first frame, use a socketed dropout. All you have to do with the stays is measure and cut them straight, which is easier than slotting.
Make your own forks? Otherwise, Wound Up or Enve
Suppliers: best known are Nova, Pacenti, and Henry James in the US and Ceeway in the UK.
#3
Senior Member


Joined: Feb 2012
Posts: 19,371
Likes: 5,515
From: Rochester, NY
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
Nothing wrong with using off road tubes for a road bike, as long as all the dimensions match up otherwise, and you are looking for the ride quality that the diameters and wall thicknesses will give you. As an example I have used an externally butted seat tube for a couple of lugless road frames.
I always felt that a slot and tab stay/drop out was easier to do and allowed for some measuring/cutting fudge. The Bb shell choice might be the bigger challenge. Not having stay sockets will make it's set up and brazing/clean up more involved. Geting the rear triangle of a frame spot on it diffecult enough with a lugged shell, adding the need for perfect stay length matching and placement on shell just increases the chance for something to be off a touch.
By all means consider making your own fork. In fact you might do the fork first. Andy.
I always felt that a slot and tab stay/drop out was easier to do and allowed for some measuring/cutting fudge. The Bb shell choice might be the bigger challenge. Not having stay sockets will make it's set up and brazing/clean up more involved. Geting the rear triangle of a frame spot on it diffecult enough with a lugged shell, adding the need for perfect stay length matching and placement on shell just increases the chance for something to be off a touch.
By all means consider making your own fork. In fact you might do the fork first. Andy.
#4
Randomhead
Joined: Aug 2008
Posts: 25,930
Likes: 4,825
From: Happy Valley, Pennsylvania
supplier thread
I don't read sticky threads either.
Mountain bike top tube and down tube are longer due to the handlebars. One of the steps in designing a frame is making sure that you have enough butt left on the tube after you cut it to length. This could be problematic with a MTB tube on a road bike.
I don't read sticky threads either.
Mountain bike top tube and down tube are longer due to the handlebars. One of the steps in designing a frame is making sure that you have enough butt left on the tube after you cut it to length. This could be problematic with a MTB tube on a road bike.
#5
Senior Member


Joined: Jun 2006
Posts: 21,860
Likes: 3,748
Your frame geometry dwg. is based on tube centers, not a bad thing, but you have chosen an oversized tube set, fleshing out the drawing with tube diameters might show you things that do not show up yet.
Decide on your front fork before you make the frame, maybe even build it first then lock in the frame geometry for the same reasons, or buy it and have it in your hands. Decide on the brake type now too and allow for it, and tire range or choice. Assuming no fenders from what I see so far. Measure the front center dimension, distance from bottom bracket center to front axle center. The fork rake appears as if you have a dimension, but its not shown. Might as well know your trail number too for reference.
Decide on your front fork before you make the frame, maybe even build it first then lock in the frame geometry for the same reasons, or buy it and have it in your hands. Decide on the brake type now too and allow for it, and tire range or choice. Assuming no fenders from what I see so far. Measure the front center dimension, distance from bottom bracket center to front axle center. The fork rake appears as if you have a dimension, but its not shown. Might as well know your trail number too for reference.
#6
Thread Starter
Junior Member
Joined: Aug 2012
Posts: 5
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Thank you all for the replies, I am learning more from your responses.
For Oversized frames, does that just mean longer parts so i can just cut off what is not necessary?
For Oversized frames, does that just mean longer parts so i can just cut off what is not necessary?
Last edited by mostyle07; 08-05-12 at 04:08 AM.
#7
Thread Starter
Junior Member
Joined: Aug 2012
Posts: 5
Likes: 0
You realize you've selected an off-road tubeset for a road bike, right?
Use 36mm head tube for a 28.6mm (1.125") steerer. It is the modern standard for most frames, though some builders still use 1" steerer/31.8mm head tube, usually so they can used threaded headset & quill stem (which I prefer)
For your first frame, use a socketed dropout. All you have to do with the stays is measure and cut them straight, which is easier than slotting.
Make your own forks? Otherwise, Wound Up or Enve
Suppliers: best known are Nova, Pacenti, and Henry James in the US and Ceeway in the UK.
Use 36mm head tube for a 28.6mm (1.125") steerer. It is the modern standard for most frames, though some builders still use 1" steerer/31.8mm head tube, usually so they can used threaded headset & quill stem (which I prefer)
For your first frame, use a socketed dropout. All you have to do with the stays is measure and cut them straight, which is easier than slotting.
Make your own forks? Otherwise, Wound Up or Enve
Suppliers: best known are Nova, Pacenti, and Henry James in the US and Ceeway in the UK.
- https://www.cycle-frames.com/bicycle-...CRTS_AERO.html
- https://www.cycle-frames.com/bicycle-...-TUBE-SET.html
- https://www.cycle-frames.com/bicycle-...D-TUBESET.html
for the dropouts, would recommend horizontal, semi vertical, or vertical?
I may consider making my own forks, but is that more challenging than frame building?
Thanks again
#8
Thread Starter
Junior Member
Joined: Aug 2012
Posts: 5
Likes: 0
Your frame geometry dwg. is based on tube centers, not a bad thing, but you have chosen an oversized tube set, fleshing out the drawing with tube diameters might show you things that do not show up yet.
Decide on your front fork before you make the frame, maybe even build it first then lock in the frame geometry for the same reasons, or buy it and have it in your hands. Decide on the brake type now too and allow for it, and tire range or choice. Assuming no fenders from what I see so far. Measure the front center dimension, distance from bottom bracket center to front axle center. The fork rake appears as if you have a dimension, but its not shown. Might as well know your trail number too for reference.
Decide on your front fork before you make the frame, maybe even build it first then lock in the frame geometry for the same reasons, or buy it and have it in your hands. Decide on the brake type now too and allow for it, and tire range or choice. Assuming no fenders from what I see so far. Measure the front center dimension, distance from bottom bracket center to front axle center. The fork rake appears as if you have a dimension, but its not shown. Might as well know your trail number too for reference.
are disc-brakes worth the cost and also mechanical disc vs hydro disc. Alot more to learning for me to do!
#9
Thread Starter
Junior Member
Joined: Aug 2012
Posts: 5
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supplier thread
I don't read sticky threads either.
Mountain bike top tube and down tube are longer due to the handlebars. One of the steps in designing a frame is making sure that you have enough butt left on the tube after you cut it to length. This could be problematic with a MTB tube on a road bike.
I don't read sticky threads either.
Mountain bike top tube and down tube are longer due to the handlebars. One of the steps in designing a frame is making sure that you have enough butt left on the tube after you cut it to length. This could be problematic with a MTB tube on a road bike.
#10
Randomhead
Joined: Aug 2008
Posts: 25,930
Likes: 4,825
From: Happy Valley, Pennsylvania
as far as disk brakes go, they are a little more complicated and I'm not sure I would bother on a first frame. A fork will require fixturing to put the tabs on, you can get rear dropouts with tabs built in. My LBS is a proponent of mechanical brakes. If you are building a drop bar road bike, mechanical is much easier.
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