kingpin breaking in half

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Apr 15, 2013
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Washington state
out camping with wife at Fort Stevens Oregon with LOTS of bike paths.
Rode my street fox several days and the last day I accidentally got the left front wheel in a hole. I thought I herded something snap?
Following day I started riding w/ no issues BUT then I had to pickup the front right wheel to get trike turned around, the kingpin fell out, bearings etc.
put all back in and trike rides ok.
Have always been worrying about the kingpin breaking seeing how thin the pin is and having to shorten while building the trike three years ago but no issues until now.
Thinking of "HOW TO BUILD A BETTER MOUSE TRAP" in this case a better method to shorten a kingpin. Several ideas, use a thicker tube for kingpin but the threads are then an issue. Another idea is use sealed bearings with a flange and use a 3/4" bolt for kingpin. Could just blind weld a steel rod inside the existing pins.
Am thinking ahead for the Recon Lizard project as it will have 26x4 wheels on all three wheels. LOTS more stress on kingpins etc.
And yes it broke above the weld and had plenty of penetration.
 
Joined
Apr 15, 2013
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Washington state
finding a tap to re
thread
will look at all my options when I get home. The flanged bearing idea seems the easiest and I have both, DOM tubing and bearings for the hubs.
 

Radical Brad

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Kakabeka Falls, Ontario, Canada
Do you have a photo?
Not sure if you mean the fork stem has separated or the axle from the wheel hub.
If this is the fork stem, then did it break at the base or where you might have done shortening surgery?

A photo would be great. I have tortured these beyond all sanity and bent more than a few, but never seen one snap.

Thanks,
Brad
 
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South Benfleet, Essex, England, UK
My shoulder attests to my ability to break a badly welded/shortened king-pin. Mea-culpa; rubbish welding on my part, it was wafer thin and weak.
6-weeks of post-surgery agony and all was then ok again. Lesson learned.
 

Radical Brad

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The emergency room has seen plenty of my welding mistakes back in the day as well!
I would say that in my teens, I had one stitch per inch of weld.
Of course, I only had access to brazing torches back then, and had no idea of trusses or gussets!

Brad
 
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