Snapped the steerer on my home made forks

The other day I took a break from working on the build for my Morini powered imitation board tracker and took it for a short ride to the corner store, which is only about 1/4 mile away. Hadn't gone more than a couple of blocks and had the bike "wound out" hauling ass down a short hill. I saw a car, on the next side street ahead, pull up and stop at the stop sign. A little voice in my head said, "I bet they're gonna pull out in front of me"...little voice was right...that's just what they did.

Back pedaled my coaster brake and pulled hard on the hand lever for my front roller brake. The front of my bike lurched up in the air then came right back down like I had just run over a dog or something. Scared the CRAP outta me, but all was cool. I didn't lose control and was able to slow down enough that the car got past me before I hit it.

Had no idea why the bike had lurched up like that but seemed to be riding just fine so I continued the rest of the way to the store, got what I needed then rode back home. Once home and wondering why the bike lurched like it did I grabbed the hand brake and started rocked the bike back and forth. Hrmmm, thinking to myself, those fork blades sure seem to be bending forwards and backwards an aweful lot...then *SNAP* the steerer tube snapped right in half the forks just dropped right out of the frame.

OMG! I am SOO friggen lucky!! I that steerer had snapped like that while I was riding I would have been launched right over the handlebars for a most "Gawd Aweful Flying Faceplant" that it still makes me shudder to think about it.

I made my home made monarch style forks using the steerer and crown from a Worksman bicycle. Worksman bikes are built tough and I'm surprised the steerer tubing snapped in two like that. I have no idea what made it snap like that other than some probably some ID-Ten-T error on my part, if you know what I mean.

Oh well, whatever the reason it happened, at least I know my brakes work GREAT!

Got around to fixing my forks today. Found what really happened. It appears that someone (doubt it was Worksman but I don't know for sure) took a front fork with a shorter steerer and extended the steerer to fit the longer Worksman fork tube. The concept was good but the brazing between the steerer plug to the crown's tube insert was VERY weak.

Picture speaks 1000 words.

Actually, my diagram was a bit incorrect in displaying the plug as solid. It has about a 3/8" hole through it. It was also turned on a lathe where it is thick at one end to fit inside the steerer tube and thinner on the other side to fit in a hole in the top insert tube which is the part of the crown that fit inside the original steerer.

You're right in guessing that it was a cold weld. The brazing barely penetrated beyond the surface of the steerer. There was no brazing at all on the plut or the crown insert.

I LOADED it up with Silver Brazing rod. Used almost 1/2 stick and got it plenty hot enough to penetrate deeply.

I'm not so sure about what you said that high heat would embrittle the steerer. Heating or annealing metal is what you do to make it softer and more ductile, releaving internal stress in the metal.