# Bicycle Frame Jig



## DSaul (Apr 19, 2016)

I build bicycle frames as a hobby and built my first frame jig about 5 years ago.  That original design has evolved quite a bit over the years and also led me into machining as a hobby.  I learned what needed to be adjustable and where the pivot points should be to make it easy to set up.  This is the second of this version that I have built for someone other than myself.  Some of the ideas have been borrowed from other frame jigs and I make no claims that this is an original design.


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## TommyD (Apr 19, 2016)

Nice work. Is that Bosch made structural materials you used?


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## DSaul (Apr 19, 2016)

Thanks.  The extrusions are 40 series metric from 8020.


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## mikey (Apr 19, 2016)

Very nicely done!


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## Billh51 (Apr 19, 2016)

Nice work, looks very professionally done. You should post some pictures of the bikes you build on it.


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## DSaul (Apr 20, 2016)

These are some of the most recent bikes I have built.


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## mattthemuppet2 (Apr 20, 2016)

very cool and beautifully made bikes too. Are the sliding dropouts on the 2nd frame (SS only?) made by you or do you order them in? Also, the seat tube angle, is that set using that slotted adjuster and pivots at the bottom of the jig (where the BB shell will be)? How do you set angle, with an angle block or protractor, or is there a scale on there? The guy that repaired my mtb frame in central PA (cracked chainstay) had a funky horizontal jig with holes drilled into it all over the place for setting angles.


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## DSaul (Apr 20, 2016)

mattthemuppet said:


> very cool and beautifully made bikes too. Are the sliding dropouts on the 2nd frame (SS only?) made by you or do you order them in? Also, the seat tube angle, is that set using that slotted adjuster and pivots at the bottom of the jig (where the BB shell will be)? How do you set angle, with an angle block or protractor, or is there a scale on there? The guy that repaired my mtb frame in central PA (cracked chainstay) had a funky horizontal jig with holes drilled into it all over the place for setting angles.



The sliding dropouts on the MTB are from 2Souls cycles in Germany.  The sliders are single speed only, but they are available with a derailleur hanger and 12mm Thru axle styles.  Its just a matter of switching the sliding component.  

The seat tube angle is adjusted using the curved slot on the back of the plate and it pivots around the 3/4" shaft that functions as the bottom bracket mount.  The angle is set with a digital angle gauge, after zeroing the gauge on the spine of the jig.


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## mattthemuppet2 (Apr 20, 2016)

I thought I'd seen them before, they're really neat. Great way to have your SS cake and eat it too


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## spacecadet (Apr 25, 2016)

amazing! have you had any issues with the 8020 extrusion and resulting flatness?


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## DSaul (Apr 26, 2016)

spacecadet said:


> amazing! have you had any issues with the 8020 extrusion and resulting flatness?


 I've had no issues with flatness, they are sufficiently flat for this application .  There are some variations in the dimensions from piece to piece.  Its not usually a problem, but it can add up on stacked pieces.  The biggest variance has been the width of the slots, so I guess thats not a critical dimension for them.


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## Billh51 (Apr 27, 2016)

Thanks for posting the pictures, sleek design and quality work.


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