Filed In: Process

Father/Daughter Project - Part 11

January 17, 2020   |   Chris Blandford

All right, moving on. For today:

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16. "Bridges"
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I've only ever made bridges out of round tubing, but I thought I’d try something different on this little bike. I like the look of the plate reinforcements I’ve seen on a few different mixte-style bikes. So, I decided to ditch regular, round bridges all together and purchased some 4130 sheet steel from Aircraft Spruce.

I started with poster board (actually, this was a manilla folder that was within arm’s reach). I traced and trimmed until I had the pieces and shapes that I was satisfied with. Then I transferred the shapes on to the steel and cut them out with a cutting wheel, cleaning them up with files and checking that they fit well.

Filed In: Process

Father/Daughter Project - Part 10

January 14, 2020   |   Chris Blandford

Back at it:

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15. Top tubes / Seat stays!
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Lots of considerations for these top tubes/seat stays. Before I started this bike, I knew I wanted these tubes to be swoopy-curvy. So, I impulse-purchased a Harbor Freight tubing roller and some small-diameter dies from Swag Offroad. When I got the roller home, I ran a couple test pieces. I’d never rolled tubes before. Super fun. I’m definitely going to use this in the future, for a variety of things.

I wasn’t able to find any definitive information on how to achieve this style of mixte-esque stay, so I had to wing it a bit. I began by rolling the tubes (went with .5”) across their entire length, holding them up to the frame to check the radius as I went. I rolled little by little until I was satisfied. No drawing here, just building in space.

Filed In: Process

Father/Daughter Project - Part 9

January 10, 2020   |   Chris Blandford

Onward.

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14. Finish Main Fillets
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To finish my fillets, I follow the method described in these two links:

Steve Garro: Polishing Fillet Brazes
Dave Kirk: Fillet Show Bike

I start with round files, moving from larger to smaller. The largest file takes out all of my little bronze-dime edges; the medium and small smooth everything out. The smaller the file, the closer I get to the edge of the fillet, and the lighter I press. I avoid filing on the tube itself--I (try to) only file the fillet. I work in a short, almost side-to-side pushing motion as I file.