Picture of Bicycle Frame Building Jig
A little over a year ago I took a bicycle frame building class through the United Bicycle Institute. I attended the chromoly brazing class at their Portland campus. Since then I have wanted to build more bike frames. I am interested in making money doing it, and perhaps someday, making it my sole source of income. On the path to becoming a bicycle frame builder one of my biggest obstacles is acquiring a frame building jig. They are expensive, arguably the most expensive single tool you need to accurately build quality bicycle frames. So I, like many bicycle frame hobbyists, decided to build by own. My personal goal for my frame jig however, was to build a professional quality frame jig. I wanted something I could potentially start a business with.
In Portland I learned to build using an Arctos jig. The simplistic, functional and approachable design seemed like an obvious choice for me. I scoured the internet for photos of bicycle frame jigs, in particular Arctos jigs. A handful of people have posted photos of Arctos style jigs that they have built. Alex Wettmore built a very close replica he called the “Arctos Clone Frame Fixture”. His photos and descriptions were helpful and inspiring.
With the Arctos model at the core of my design I started out to make changes to suit my specific needs. Some of the changes I wanted to implement included the option of simple attachments to make a tandem frame as well as room for extra long chain stays (for cargo bikes). The room for long chain stays was easy. I simply left the main spine of the jig as long as possible. I will discuss the the tandem attachment I came up with later in this instructable.
I designed specific parts of my jig as I built them. I prototyped as I constructed so you wouldn’t have to. I did not draw the entire jig in CAD. I used a variety of specific drawings and views to produce everything. I have attached all my CAD files both as original technical drawings and dimensioned labeled PDFs. This instructable will be broken down in to one step for each sub assembly of the Jig.
Some Acronyms I might be using:
HT - Head Tube
ST - Seat Tube
TT - Top Tube
DT - Down Tube
BB - Bottom Bracket
CS - Chain Stay
SS - Seat Stay
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Hi Tanner,

This is an invaluable post. I'm wondering if you kept track of the material cost and, if so, what was the final tally?

praveenp1211 days ago

Awesome instructable! Loved it ! and a superbly finished jig!
I'm planning on building one based on this instructable. But I'm not able to find drawings for the dummy axle block. Did i miss something?! It would be great if you can upload that Thanks a tonne !

dukeduck made it!21 days ago
Thanks for the instructable. I just finished mine today.
JonathanW71 month ago

Also, I can't seem find any place that sells 8020 160x40 Extrusions. 8020 sells 120x40 or 160x80 though.

JonathanW71 month ago

Do you think it possible to make this jig without access to my own machine shop?

Can a drill press substitute for a vertical mill for example?

I'll probably have to find a machine shop to machine some of the parts.

jawnn2 months ago

How can I open these dwg and dxf files?

Tanner W (author)  jawnn2 months ago
I use Autocad personally but I think there are other CAD programs that will open them.
chemin5 months ago

hi, i m going to build your amazing jig, and was wondering if there was any way you could sell me the dummy axle block?

seems impossible for me to build it.



Mrgto5 months ago
Nice work! I've been interested in building frames for a while. I have a full machine & welding shop. I need to make a jig like this.

One word of advice, buy some center drills. Drilling using a punch mark is bad technique. The drill will walk no matter what you do if you don't. Just trying to help you on your journey so don't take this as a bash!
Incunabula5 months ago

Very nice. Which T-slot nuts did you go with under the handles for the sliding elements?

Tanner W (author)  Incunabula5 months ago

I used the standard zinc-plated steel End-Feed Fasteners for Aluminum T-Slotted Framing from McMaster. In my case, I used the ones for 40mm series aluminum extrusions...

Hello, nice work.

Do you have a drawing with demensioning from the drawing of the "parts"?

I can view the drawing only without dimensions?

DevinC37 months ago

can this jig be used to make bmx frames?

Tanner W (author)  DevinC37 months ago
I think the only thing different about building BMX frames is that they typically have bottom bracket rise rather than bottom bracket drop. To make your jig capable of building BMX frames all you need is a little longer axle mount piece so you can lower the rear axle further down.
GurjotG11 months ago

Wow man, this is great work. Thank you so much for putting this up.

al_packer1 year ago
Any chance you could post your drawings in DXF format? My Turbocad 18 doesn't want to open the DWG files for some reason.
Tanner W (author)  al_packer1 year ago
I uploaded .DXF files. Let me know if they don't work either.

Great job, but i can't find your drawings/blueprints. Where are they? thanks.

Tanner W (author)  igarcia201 year ago

They are on the first page of the instructable. At the bottom of the "intro" before step one. (at least that is where they show up when I open the instructable)

They don't show up for me!! I don't get it! :( could you please send them to me!! it would be great.

Tanner W (author)  igarcia201 year ago

Does this work?

THANKS!! it works great!!

Works perfectly. Thank you!


Many thanks for all the interest.

ToddAlex1 year ago

Tanner, thank you for putting this out there! Great build and the pics are superb. I can't open any of the files though. Would you be able to email the files to me? Thanks! Todd

gmilanese1 year ago

Incredible job man, congratulations. Is there any chance that you sell a package of this jig and ship it internationally? I would like to have one but I don't have the same materials available here. Any ideas of total cost?

metalfarm1 year ago

Very cool jig, thanks for figuring this one out for us. I'm about to pull the trigger on a McMaster order and get this thing rolling, but wanted to touch on one thing first... I plan to do offset ST's to accommodate short CS's on 29's, w/o bends in the ST. I'm curious if you've come up with any mods, or have any ideas for a mod before I start construction? Again, very nice work. Thanks a bunch.


Tanner W (author)  metalfarm1 year ago
I would change the BB shell mount. When I turned the BB shell attachment points on a lathe I didn't do a very good job. They should slip fit on to a 5/8" steel rod but I used a 5/8" bit to drill the aluminum stock. The hole is too big, they are a sloppy fit.
I am going to make new BB shell "cones" but this time I will use steel (as I mentioned in the instructable). I will drill a smaller than 5/8" hole and use a boring bar on the lathe to get a perfect slip fit.
That is all I have planned for mods currently. I am hoping to build another frame next week. If I notice anything else worth changing I will message you.


Yes, that should snug things up on the BB. I wonder if the ST cone mount (AL angle) would be too difficult to build so that it pivots? I'm looking for a way to have a snug connection (at the proper angle) at the top, so I can push the bottom of the ST forward of the center of the BB a bit, even overlapping on the DT slightly. I guess I can't decide if it needs to pivot in the center of the mount, or if it should be slotted?

Thanks again, nice work.

Or another BB shell mount with an offset...

fonsu331 year ago
hello, I can not see or access the cad files ... as I can get them?

Nicely done. Excellent idea to make it usable for tandems. Also great that you are considering Cargo bikes. Too many jigs are only useful for the sort of frame you can order from QBP. My motivation for frame building is that I need a 68 or 70 cm frame and I can either build them or pay someone else to, and few builders seem to "get" that you just can't scale up the ST and HT and have a decent handling frame. I best stop before I hit full rant mode!
Tanner W (author)  gumby_kevbo1 year ago
I hear you gumby_kevbo. I got in touch with Rivendell for some of the specs from their 71cm A. Homer Hilsen while I was designing my jig. They got it right with the double top tube. With its 300mm HT the flex in the frame without a second TT would be crazy.
guyguy691 year ago
Great job, Very professional!
I'm wondering if this could this be adapted to making Motorcycle Frames?
Tanner W (author)  guyguy691 year ago
I don't know much about motorcycle frames but I imagine you could modify the design to work with them.
Very professional work! Out of curiosity, what frame are you building in step 10? A transport bike with a top tube curved upwards near the head tube?
Tanner W (author)  ElegantAndrogyne1 year ago
Thanks ElegantAndrogyne! Yeah, curved top tube cruiser, easiest to just share a picture of the finished frame. Built up with a 5 speed internally geared hub. It ended up being a really fun bike.

great job! bottle opener dropout? way to go!
Tanner W (author)  ltommaso1 year ago
Yeah! Definitely put a bottle opener dropout on it! From Paragon Machine Works.
ltommaso1 year ago
great job! bottle opener dropout? way to go!
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