Re: Extensive article on Rivendell and Grant Petersen

On 9/24/2024 3:17 PM, Catrike Ryder wrote:

On Tue, 24 Sep 2024 14:14:41 -0400, Frank Krygowski
<frkrygow@sbcglobal.net> wrote:
 

You might do well to read some of the archives of this group. There have
always been people posting opinions that were factually wrong, and there
have always been people pointing out those mistakes. As I've noted
earlier, having mistakes pointed out is a necessary part of the process
of education.

 That's fine of the person being corrected understands that the
corrector is qualified to do so and is truly interested in making
things better. In my opinion, you fall far short of both those
standards.

Your opinion on that matter is worthless. You don't have anywhere near the background needed to judge technical proficiency. Professional Engineering licensing boards of two different states have disagreed with you, not to mention those conferring my engineering degrees and those institutions for whom I've worked.

There are many examples of ideas that were posted frequently, and noted
as wrong. Most of them seldom pop up any more - and not only, I think,
just because there are fewer posts. I think people actually learned things.
>
Examples of mistaken claims? Chains wear by stretching the metal. Old
frames get "soft." Increasing spoke tension makes a wheel more rigid.
Tying and soldering spokes makes a wheel stronger. Headsets fail by true
brinelling due to impact loads. Hanging a bike by the front wheel makes
the spokes stretch... and many more.
>
BTW, what was that stopping distance from 20 mph again?  ;-)

 20 MPH would be maybe 9/10 feet if I didn't concern myself with
slamming the chain rings into the ground or doing a face plant on the
ground in front of the bike. 30 MPH would be a little further. Two
front brakes work better than one, especially when the rider's weight
is already more over the front wheels before he applies the brakes.

Right, good one. There is no way you can stop your tricycle in 10 feet from 20 miles per hour. That would require a deceleration of 43 ft/s^2 or 1.34 times the acceleration of gravity. IOW you'd need tires with a static coefficient of friction at least 1.34, plus absolutely perfect application of both brakes so that both wheels were at the absolute limit of traction but not skidding. And you'd have to be in a "nose wheelie" all the while, with your rear tire up in the air so every bit of your weight was on the front wheels. It's essentially impossible.
For 9 feet, your acceleration would have to be nearly 48 ft/s^2, and besides absolutely perfect braking reflexes, you'd need tires with a static coefficient of friction at least 1.48.
And 30 mph would be _much_ farther, not "a little." The velocity term gets squared in the relevant calculation, much as it does when calculating kinetic energy.
I'm sure you don't know what a lot of that means. But what you're claiming is practically impossible. Feel free to prove me wrong by doing what you claim and posting video evidence.
--
- Frank Krygowski