I worked through the vintage dropouts and fork crowns today, checking the spec and getting them ready to use on Steven's build. I'm pleased with how they came out. I need to do some final machine work on them; breaking the edges, tapping the M10 derailleur threads, cutting off the material anchor holes.
With the dropouts in hand, I set to working on developing a system for bending the stays for the project. I knew this was gonna be a bugger to get right, here's why. Most Klunker style seat stays were one of two types; either they were long stays that ran from the dropout all the way to the headtube with just a single bend to meet the seat tube, or they arched up to meet a segmented joint at the seat tube. Modern adaptations have used "tee" joints to meet the seat tube or a monostay and "tee" joint to fit the rear end together. Steven wants something that looks fluid, so I played around with some options. In the end, I decided the most aesthetic and functional design would be to use a single stay with a compound bend...rolled for the constant radius into a single lateral bend to meet the seat tube. While this will look the best and offer the strongest joint, it is also very difficult to achieve.I spent the afternoon experimenting, working on a process to get both the lateral bend and the rolled radius without crimping any of the bends. I finally hit on a process that worked well and am moderately happy with the first stays. I'm gonna fine tune the dies a bit more and then make Steven's pair.
Here's a couple shots from today...
Making a new bending die to fit the 1.25 pivot post...
A top view of the seat stays with the lateral bend...these will yield 3 inches of rear tire space.
A side view of the mock stays in the fixture. I had to really arc these more than I had planned due to the short span from the dropout to the seat tube for a visual radius to be present. This is the bend I want to fine tune a bit before I make the final pieces.
I'm looking forward to doing up the plate fork crowns, I think they will compliment the style of the dropouts and really bring the bike together in a balanced look.cheers,
rody
1 comment:
Looking really good. Can't wait to see some shots of the fork coming together.
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