First frame design & build log

I’ve had a set of tubes kicking around from a delayed project I intended to start…9 years ago before we had kids :sweat_smile:. Getting back around to working on my first frame. I’ve got no jigs or fixtures, so this is going to be a little hacky! I plan to fillet braze.

Will use this thread to post progress. It is going to be a single speed cross/gravel sort of deal with some rack mounts and Paragon track ends. Building a fork is probably not advisable for my first build, so I am going to have to source a decent 100mm qr fork with canti mounts that has decent tire clearances. Ideally Ultimately I want to build up to a hardtail mtb, but I have all of the components for this build which I think lower cost entry point for me to make lots of mistakes and bring improvements to frame #2.

First two questions:

Seat tube—I got my seat tube from Nova Cycle; looking back on my order email, it was labeled: NOVA CRMO 28.6 X 9/6 X 650). Measuring with my calipers it looks like one end is 1.2mm thick (1.2/0.6/0.9). Assuming using the 1.2 is best used for the seat cluster… I’ll have to figure out how long the butt is, but at this wall thickness would it still be advisable to sleeve the ST as a reinforcement, or am I ok with this wall thickness (FWIW, bike will have a level TT, and not very much seat tube extended).

Head tube—The HT I have is 36mm with what looks to be 1.1mm thick. Should I be considering something thicker or silver brazing reinforcement rings on?

Rest of the main tubes:
Top tube: 28.6mm, 8/5/8
Down tube: 31.8mm, 8/5/8
Seat stays: 16mm (forget the rest of the details).

I have some straight chainstays, but I think I am going to purchases these pre-bent ones.


Measure the diameter of the seat tube at both ends. If it’s a bulge butted tube it should be around 29.8mm. That’s the side you’ll want at the seat cluster. You don’t need to sleeve it.

If it’s 28.6mm on both ends, the thicker end goes to the BB shell and the thinner end needs a sleeve at the cluster. Framebuilder Supply sells ready-to-use sleeves.

You’ll want to use reinforcing rings for that head tube. Metal Guru sells some.

I can’t speak to the rest of the tube selection because you didn’t provide a print of your design and your weight. Hopefully you’re using BikeCAD to design the frame. It’s totally worth the one-time fee.


Thank you so much! Diameter is definitely consistent. Will look into some options for a sleeve, and also the rings (which look to be sold out). Will see if I can source a different HT.

Working on the drawing next (I realize I am working a bit backwards, but I will driving to the US next Tuesday and trying to pick up everything I need, at least the bigger stuff, to avoid having to ship it to Canada).

Will post a drawing soon. I weigh 145ish lbs. Frame size will be around 54cm square.

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Unless you are really set on having a skinny head tube I would suggest getting a 44mm head tube for forwards comparability if you ever decide to swap to a tapered steerer fork. I have a bike that I regret not getting a 44mm head tube for and changing it after the fact is not super easy, at least compared to putting one on right off the bat.

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It’s funny cause I would say the exact opposite. For a roadish bike (road, gravel, all-road) I think a 34mm headtube (with a straight steerer steel fork) is an absolue classic look. If you wanted a bit more compatibilty then 37mm is the other option. On a MTB 44mm all the way for sure!

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I was on the fence about HT size. I intend to run a straight steerer cross fork for canti bosses if I can find something with decent tire clearance. Definitely do like the look of the smaller HT for a bike like this from an aesthetics POV.

Disc brakes and tapered steerers open up a lot more options because I can tap into the modern gravel stuff. It just means in addition to the fork, I need to rebuild wheels, find hubs, and brakes and rotors. Ultimately I see this as practice and I want to port over the build that I have on the bike below, except with with track ends (instead of the sometimes-creaky EBB), and bigger tire clearances.


Agree with the HT size, fork compatibility, and aesthetics being an issue. This is why I am working hard on the EC37 project and 1.25 tapered forks.

Here are a few cantilever, straight steerer forks to get the convo started.

Surly Cross Check: Cross-Check Fork | Road Forks | Surly Bikes | Surly Bikes

  • 29x2.0
  • 400a2c
  • 44mm offset

Ritchey Cross: WCS Carbon Cross Canti Fork

  • 398 a2c
  • 700x45
  • 45 offset

New Alibon (soma): New Albion Fork Privateer Matte Blk | Soma Fab Shop

  • 390 a2c
  • 700x42
  • 50 offset

whisky: No.7 QR Canti Cyclocross Fork | Whisky Parts Co

  • 395 a2c
  • 700x38
  • 47mm offset
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Thanks! I believe there is an older Whisky fork with 50mm, but its hard to know if that is what you’re going to get when you order it (I am always fearful of outdating listings using old photos but actually shipping the current version). I am definitely considering the Ritchey, and also this one from Soma with the straight blades may play nicer with a fillet brazed frame:

Soma straight blade canti cross fork

Doing a disc version would simplify a lot of this for me, but I would rather put those funds into frame 2 (29er hardtail with 44mm headtube, paragon sliders, T47, etc) where I need to buy all new kit (everything else I own is all quick release!)

Long term (if I felt confident in my skills enough to attempt a fork, a segmented fork would be sweet, and IMO those can sometimes look pretty bad with a big diameter HT and the step down to much narrower crown)


If ya going the horizontal TT look with rim brakes I think a curved blade fork with a cast crown looks bettter, regardless of whether the frame is TIG’d or brazed. For a sloping TT bikeI reckon straight blade unicrown/segmented has a better stance. The bike you’re building actually sounds similar to the Crust Florida Man.

Love where ya going with this anyway. And that hardtail sound ace too!

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