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Deep in the engineering weeds of frame design

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Deep in the engineering weeds of frame design

Old 01-22-21, 05:37 PM
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Korina
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Deep in the engineering weeds of frame design

Mr. Wildeberry, professional engineer, has been using his sick skillz to explain why Ms. Cools' custom bike has an oversized top tube. Also, speed wobble/shimmy; what is it and how to avoid it. So get yourself a really hot cup of tea (for the Brownian motion) and settle in.


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Old 01-22-21, 05:59 PM
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unterhausen
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I tediously watched through the second video until I found out the fork can't turn. I hate to be too critical, but if you are going to talk about bicycle dynamics, that is the single most important element. The rest of it could be a rigid body as far as I'm concerned.
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Old 01-22-21, 10:07 PM
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woodcraft
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2nd video:

"You will see that... wait, what's going on... that's odd...
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Old 01-23-21, 05:49 AM
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Sounds like a problem that might have been solved with the 1990s style ovalized tubing like the Columbus MAX or Univega's Biaxial Power Oval frames. Although I can't tell whether my Univega frame is stiffer than any other steel frame -- the fork is so flexy it's almost like a suspension fork. It just looks cool.
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Old 01-23-21, 06:25 AM
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Found this to be interesting and did not figure the seat tube flexing as demonstrated. Something to think about when designing a frame.
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Old 01-23-21, 07:56 PM
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Originally Posted by canklecat View Post
Sounds like a problem that might have been solved with the 1990s style ovalized tubing like the Columbus MAX or Univega's Biaxial Power Oval frames. Although I can't tell whether my Univega frame is stiffer than any other steel frame -- the fork is so flexy it's almost like a suspension fork. It just looks cool.
Is it? I can't tell; the bike appears to be invisible. {she said pointedly}
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