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Father/Daughter Project - Part 11

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Father/Daughter Project - Part 11

Friday, January 17, 2020   |   Chris Blandford

All right, moving on. For today:

16. "Bridges"

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.

Next, I (blue) fluxed and (bronze) brazed the plates in place. I tried to be mindful about the already-finished fillets around the seat stays/top tubes. I think I’ve read that remelting bronze--already on a frame--takes a little more heat than initially melting it. That matches my experience in this instance. (Also, note the little makeshift magnet-slash-clamp-slash-vise-grip fixture. Much to my surprise this worked pretty-ok, unlike some of my previous slapped-together holding techniques.)

Once all of my little plates were brazed in, I soaked and cleaned them up in the usual fashion. I also added a little bridge between the top tubes, about halfway between head tube and seat tube.

Overall, while I do like how these look, they definitely give the little frame a wicked/sharp/brutal personality. I'm not sure they compliment the curves of the stays as well as I'd thought they would. They certainly don't scream "Pink Giraffe". Oh well... It was something new to try. Mathilda thought they were neat when I shared my progress, so that makes me feel good. (And yah, about that one asymmetrical plate... I have a plan for that down the road.)

Next up are some head tube reinforcement rings and a seat tube collar. Then it’s on to the fork.