Framebuilders - Building a bicycle frame for the first time. Questions about head tube sizes.

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mostyle07
08-01-12, 03:53 AM
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 : http://www.cycle-frames.com/bicycle-frame-tubing/NOVA-OS-MTB-TS-W-SBEND-CS-and-SS.html
Bottom Bracket : http://www.cycle-frames.com/bicycle-frame-tubing/LUGLESS-SUPER-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
264770

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 264771
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


mudboy
08-01-12, 06:46 AM
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.

Andrew R Stewart
08-01-12, 09:01 AM
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.


unterhausen
08-01-12, 11:35 AM
supplier thread (http://www.bikeforums.net/showthread.php/775610-Framebuilding-Suppliers)

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.

repechage
08-01-12, 04:21 PM
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.

mostyle07
08-05-12, 04:05 AM
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?

mostyle07
08-05-12, 04:07 AM
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.

I remember making that same mistake before, choosing the MTB frame, I went to pick out some more frames. Do you guys recommend any of them?

- http://www.cycle-frames.com/bicycle-frame-tubing/NOVA-ROAD-AERO-TUBESET-MEGA-35-TT-AND-MEGA-42-DT-NOV_CRTS_AERO.html
- http://www.cycle-frames.com/bicycle-frame-tubing/NOVA-DOUBLE-OVERSIZE-ROAD-TUBE-SET.html
- http://www.cycle-frames.com/bicycle-frame-tubing/COLUMBUS-SL-ROAD-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

mostyle07
08-05-12, 04:17 AM
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.

Over sized tube sets just means longer part? does that mean that I could just resize it for my drawing?
are disc-brakes worth the cost and also mechanical disc vs hydro disc. Alot more to learning for me to do!

mostyle07
08-05-12, 04:20 AM
supplier thread (http://www.bikeforums.net/showthread.php/775610-Framebuilding-Suppliers)

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.

Thank you! must have missed that one somehow haha. Thank you for the comment, I have started to look in to different road sets above.

unterhausen
08-05-12, 02:51 PM
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.