BIG UPDATE!
On Sunday, I met up with my friend Allan and got to work on the heavy fabrication needed to transform Mutt into a BMX bike. I figured it'd all go by quickly, and we'd have enough time to make a little extra progress on
another bike of mine, but things didn't pan out at all like I expected.
First, I needed to redesign my gusset template, as the previous one was too large. Once that was done, Allan and I needed to test out my dad's 1 1/2" hole saw for this idea I had for the hole in the gussets. Turns out that not only was the hole saw not perfectly round and slightly larger than 1 1/2 inches, but the center drill bit was crooked as well. Fortunately, we were able to adjust the hole saw with a hammer to the diameter we needed, and Allan had plenty of drill bits to replace the crooked one. UNfortunately, most of the drill bits he swapped into the hole say either became crooked themselves, or they BROKE entirely! I think we went through at least 8 different bits in at least an hour before we could finally drill a good 1 1/2 inch-diameter hole consistently.
Once the hole saw problem was sorted out, Allan suggested cutting the holes out of the scrap steel plate I had before cutting the gussets out themselves. So we lined up the carboard template with a hole as best as we could, taped it to the metal, and then Allan cut along the template with a cutoff wheel.
Then he used the first cut gusset as his template for the next one.
Allan then showed me how to use the "soft wheel" as he calls it, and I ground the 2 gussets to a nice, smooth finish. Got to say, I was pretty nervous using this tool at first. I'm always a bit hesitant to use tools that I have next to no experience with, especially when I know I can get seriously hurt by them, but after a few passes with the soft wheel, I managed to get a lot more comfortable using it. Got to say, I'm pretty proud of how I did my first time around!
This is the part where I have to confess something: My original plan was to learn how to weld on this bike by welding the gussets to the frame myself. Unfortunately, I did not do well on my practice pieces at all this time, and I sheepishly chickened out of welding on the bike itself. I pretty much learned that day that I can hold just about anything steady except for my own two hands. Kind of critical when you're trying to avoid melting a hole though steel. Welding is an artform, but unlike working with pencil and paper or the pen tool in Photoshop, there's no eraser to clean up your mistakes.
That said, I
can still say I welded on some parts of the bike! Admittedly, all I did were a few tack welds to the gussets, and Allan still had to add a little more to some of them, but I'm still pretty happy with the results!
This is where I reveal my favorite part of my whole plan for these gussets. I didn't want the gussets to be just two flat plates with a simple hole drilled through them; I wanted to make these gussets look dimple-died like a factory piece. Problem is, neither Allan nor I have a dimple die tool, but I had two Schwinn fork races that were too rough to use for their original purpose, and they both were almost the same width as my scrap plate of steel!
Turns out the underside of those old Schwinn races have a really nice shape that feels like a dimple-died hole!
Allan had an idea to hid most of the welds that held the gussets to the frame on the inside, with only the front-most welds being visible on the outside.
Allan also came up with the idea of using one of the drilled-out holes as a tab to mount the chain guard to the frame. Originally, I had planned to weld a couple gussets to the dropouts, but after the hassle of making and installing the 2 main gussets at the front of the frame, and because it was getting late, I figured a simple tab would do. Besides, some of those early 70s BMX bikes didn't have rear gussets either, so it'll still look "period-correct."
After all the welding was done, Allan helped me adjust and trim the fender and chain guard to fit the frame, and I reassembled Mutt to get a better look. It could still use a bit of refinement, but overall, I'm happy with the progress we made on Sunday! I may not have learned as much about welding as I had hoped, (other than I'm really bad at it,) but I still got to learn how to use a tool I never messed with before, and it's not like I can't do more work on the bike myself!
Once I brought Mutt home, I got some better pictures of the work that had been done.
I'll need to do some sanding and filing to clean up everything, and the chain guard needs adjustments, but overall, I'm happy with the end result. That said, I feel like some of the work could use body filler before I get the frame power coated. Does anyone know of some good powder coat-safe metallized filler I could get in small, inexpensive quantities? I may not be cut out for welding, but maybe I could fare better in body work.
