Make sure that you have the correct spoke tension that we won't tell you... GRRR.
06-10-19, 01:39 PM
#26
Senior Member
A word about engineering. Bicycle wheels can be built under one pound. Normal consumer wheels around a pound and a half. Rear weighs a little more because of freehub. That wheel is expected to carry a load of 240# plus the weight of bicycle. On limiting hills the front wheel may lift off ground if effort is not expended to keep it down. All weight on just one wheel. And that wheel is expected to take torque and transmit power. And absorb shock. And side load. Downhill all weight is on front wheel. Throw in deceleration at 0.5 or maybe 0.6g. Now hit a pothole. This is more than 400 pounds of load on a 1 pound structure before the pothole. This is not normal engineering.
My favorite PhD engineer is the creator of the world's first and only million amp switch. Yes, they tested it and it worked. He looks at my bicycles and says "You know that is impossible. That bicycle does not exist."
If circumference of wheel is on order of 2 meters that is 500 cycles of reversing stress per kilometer. 20,000km is still a young wheel. Ten million cycles. The spoke doesn't even fit the hole all that well. Has a bend in it right where you don't want it. If the spokes start to break at only 20,000km usually it will be possible to find cause of early fatigue and do better next time.
My favorite PhD engineer is the creator of the world's first and only million amp switch. Yes, they tested it and it worked. He looks at my bicycles and says "You know that is impossible. That bicycle does not exist."
If circumference of wheel is on order of 2 meters that is 500 cycles of reversing stress per kilometer. 20,000km is still a young wheel. Ten million cycles. The spoke doesn't even fit the hole all that well. Has a bend in it right where you don't want it. If the spokes start to break at only 20,000km usually it will be possible to find cause of early fatigue and do better next time.
06-10-19, 04:11 PM
#28
Generally bewildered
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Hopefully, my persistent nerdiness and annoying exactness will make me your new favorite. Bwua hah hah.
I feel the same way about airplanes. Aerodynamics is a lie. They fly by magic. If the Good Lord wanted man to fly, he would have designed bigger birds.
Yes. In my case I suspect that this wheel will long outlast me. I definitely am sensing the the Karma-foo that folks feel about building their wheels. In my case, it also brings back memories of the bike shop I worked at. The owner's son was prodigiously skilled at assembling a wheel, starting with the VAR nipple driver. This was like a Yankee screwdriver. Watching Perry was amazing.
If circumference of wheel is on order of 2 meters that is 500 cycles of reversing stress per kilometer. 20,000km is still a young wheel. Ten million cycles. The spoke doesn't even fit the hole all that well. Has a bend in it right where you don't want it. If the spokes start to break at only 20,000km usually it will be possible to find cause of early fatigue and do better next time.
Last edited by WizardOfBoz; 06-10-19 at 04:29 PM.
06-10-19, 07:12 PM
#29
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