njkayaker

For our next trick, we turn a bear into a squid.

SteveG23

Ah, yes. I am on "the full website," but usually have no reason to look at the index. (Thanks for the "welcome," but I have been using "the internets" professionally since about 1987, and the WWW since no later than 1993.)

livedarklions

I think you beat me my WWW usage by approximately one year, so I'm a bit shocked you're not familiar with the concept of web page.

SteveG23

Give me a break. That's not what "web page" means.

livedarklions

We're on page 12 of the thread. Look at the URL at the top of the page, notice how it ends in 12 right before the .html?

It absolutely is a web page.

SteveG23

We shouldn't even be debating this here, but I hate to see misinformation persist. A web page is any HTML document posted for browsing via a Web browser. In this case, the "page" is generated on the fly from the postings in sequence. If you look anywhere in the thread (other than the beginning) and scroll up, you will see all the previous postings, and the URL in the Location bar will change from -bike-12 to -bike-11 to -bike-10, etc. You will see them all because it is one "Web page." If you view the HTML source, you will see that the entire thread is one HTML document (or Web page), with internal markers designating groups of postings as "pages" for indexing purposes. What is indexed as "page 12" is not a separate Web page from "page 11" or anything back to "page 1." Calling something a "web page" does not refer to a single HTML document being indexed as "pages." So yes, for purposes of this forum, we are on "page 12" of the discussion, but that has nothing to do with being "familiar with the concept of web page." That is not "the concept of web page."

terrymorse 

I did look at the source, and that is not true. A multi-page BF thread consists of several separate HTML documents (or Web pages).

For definition, a Web page is an individual HTML document.

Each "page" in a BF thread is a distinct and separate HTML document. Each "Prev" or "Next" link press queries the server, which returns a distinct HTML document.

For example:

• page 9 is a 36.49 kB document named 1230788-bike-science-more-than-1-way-turn-bike-9.html
• page 10 is a 30.76 kB document named 1230788-bike-science-more-than-1-way-turn-bike-10.html

Those are distinct HTML documents, and therefore separate Web pages.

livedarklions

Yeah, no, it's a series of HTML pages, each with its own distinct URL (to the left of the .HTML) linked by the infinite scroll feature.

The main question, though, is how one steers out of infinite scroll, which will definitely land you on your butt.

I can argue semantics of "when is a page not a page" with you all day, but watching you defend your misconceived snark has gotten dull.

70sSanO

If you are suggesting... web science: more than one way to turn a page, then you get the gold star for the day.

Good job!

John

livedarklions

I think it has something to do with pushing the right mouse button when you want to go left or something. Swoopy mouse motions are my forte.

Kort

Remember vector analysis from your physics class? No? I don't blame you! That boils down to saying you can describe horizontal and vertical forces by drawing a triangle. If the bicycle is leaning in a turn, the angle of lean is the hypotenuse of a triangle. If you dropped a plum bob straight down, that would represent the amount of vertical force the tires are applying to the pavement. If you drew a line from where the plumb bob touches the pavement over to the contact patches of the tires you would see how much lateral force the tires are applying. At a 45-degree lean, your vertical force and lateral forces are the same. The amount of lateral force required to get through the turn is determined by the centrifugal force. That is a combination of speed and radius of the turn. In a given turn, at slow speeds, the amount of centrifugal force is small so the line from the plumb bob to the contact patch is short and the vector analysis shows that most of the force is vertical and just a little bit of it is horizontal; there is very little lean which is the hypotenuse of the triangle. The triangle is tall and skinny.

At high speeds there is a lot of centrifugal force, so the horizontal leg of the triangle gets long and it can approach equaling the vertical leg of the triangle: a 45 degree lean.

Anytime you are turning there is some lean because there is some centrifugal force. If you were simply to lean the bike over without turning you would do a maneuver motorcyclists call " laying it down " in which they force the motorcycle to fall down and slide on the pavement while they attempt to ride on top of it and avoid road rash.

If you think you can turn without lean, try setting up a child's model train in a circular track. On a little flat car set up a model bicycle that has a small footprint stand underneath it. At rest you can balance the bicycle vertically. As soon as you start the train going around the circle the bicycle will fall to the outside of the turn because it has no lean.

Anyway, all bicycling turns generate some lean. Steering with the handlebars turned starts a turn which generates some lean but at low speeds you hardly notice it. At high speeda You are creating a turn at the front wheel and resultant lean of the rider and cycle. The amount of handlebar turn is unnoticed by the rider, but it is there.

The phenomenon of counter staring is real and beyond my capabilities to analyze. I strongly suspect it is a gyroscopic phenomenon. Good luck figuring that one out!

Kort

Remember vector analysis from your physics class? No? I don't blame you! That boils down to saying you can describe horizontal and vertical forces by drawing a triangle. If the bicycle is leaning in a turn, the angle of lean is the hypotenuse of a triangle. If you dropped a plum bob straight down, that would represent the amount of vertical force the tires are applying to the pavement. If you drew a line from where the plumb bob touches the pavement over to the contact patches of the tires you would see how much lateral force the tires are applying. At a 45-degree lean, your vertical force and lateral forces are the same. The amount of lateral force required to get through the turn is determined by the centrifugal force. That is a combination of speed and radius of the turn. In a given turn, at slow speeds, the amount of centrifugal force is small so the line from the plumb bob to the contact patch is short and the vector analysis shows that most of the force is vertical and just a little bit of it is horizontal; there is very little lean which is the hypotenuse of the triangle. The triangle is tall and skinny.

At high speeds there is a lot of centrifugal force, so the horizontal leg of the triangle gets long and it can approach equaling the vertical leg of the triangle: a 45 degree lean.

Anytime you are turning there is some lean because there is some centrifugal force. If you were simply to lean the bike over without turning you would do a maneuver motorcyclists call " laying it down " in which they force the motorcycle to fall down and slide on the pavement while they attempt to ride on top of it and avoid road rash.

If you think you can turn without lean, try setting up a child's model train in a circular track. On a little flat car set up a model bicycle that has a small footprint stand underneath it. At rest you can balance the bicycle vertically. As soon as you start the train going around the circle the bicycle will fall to the outside of the turn because it has no lean.

Anyway, all bicycling turns generate some lean. Steering with the handlebars turned starts a turn which generates some lean but at low speeds you hardly notice it. At high speeda You are creating a turn at the front wheel and resultant lean of the rider and cycle. The amount of handlebar turn is unnoticed by the rider, but it is there.

The phenomenon of counter staring is real and beyond my capabilities to analyze. I strongly suspect it is a gyroscopic phenomenon. Good luck figuring that one out!

PS: this much I know: take a child's toy gyroscope and get it spinning. Then turn the spinning axis horizontal and position the spinning wheel like your front tire in front of you then holding your left arm steady push gently on the right knob at the end of the spinning axis on the gyroscope frame push it gently forward and you'll find that the gyroscope doesn't rotate forward like it would if you were steering it, it dips downward. Okay, that's all I can talk about on gyroscope physics. Negative steering exemplified.

Sy Reene

tomato tomatoe potato potahtoe

tomato coupe

It's tomato. Just sayin' ...

ofajen

It’s not essentially a gyroscopic effect. Experimenters have created functional bikes with extra wheels spinning the opposite way to cancel the gyroscopic forces and the bike is still stable.

How do bicycles balance themselves?

The relatively small gyroscopic forces are needed to steer no-hands, but negligible when you use the handlebar.

The key factors are the front-weighted steering geometry where steer and roll are connected and where the front steerer falls faster than the rear frame/rider.

Otto

GhostRider62

Gyroscopic effect and trail have been shown experimentally not to be required to turn.

I think the central question is whether a rider can lean without a counter steering action from the bars or front wheel.

To me, there is no question that there must be a counter force. Is this counterforce always imposed with a steering action at the handle bars counter to the desired direction. The wheels are always moving to keep the vectors happy.

My normal bike these days is a very long wheelbase two wheeled recumbent where my mass is centered but very low. This is a very difficult bike to ride and to turn in certain conditions. I use a long tiller steerer with a very small handle bar of perhaps 5 inches wide. Any movement of the front wheel is immediately translated to movement in the bars. The slightest movement in the bars and the bike will dart. It takes a slight touch to ride it. Today, I did some experiments initiating turns at 25-30 mph simply moving my CG. The front wheel counter followed the move in my body mass with no detectable counter movement felt in the handlebar or visually in the wheel itself. In other words, the counter action of the body produced the wheel to go the other way. It is possible the wheel initially moves the other way but nothing like the Rene Hearse video. It is also possible that because all of my bikes historically have had massive trail, that initiating a turn at speed takes less counter "steer" and isn't noticeable to me. I can push the bike one hand to the seat and steer it. To me, this gets to the essence of the discussion. A bike does not steer itself even given that it is "stable" from a control standpoint. If I can initiate a turn with change in body position without using my hands on the bars, my body is steering the bike not my hands on the handle bar.

This video shows some of the experiments debunking trail and gyro

AlmostTrick

And what you do with your hands on the bars can easily negate these changes you make in body position, while body position cannot negate what you do with your hands. Ever carry a squirming kid in a carrier, or a load flopping around in a basket?

At the very most, your body position may aid a small amount while working in unison with your hands, but the hands are calling the shots.

Thomas_Faulkner

I have always loved the exact sciences and it seems to me that even on bicycles you can apply physics or mathematics. I love building and assembling different vehicles and am studying to be a rocket scientist. By using https://plainmath.net/post-secondary...lace-transform I hope to quickly resolve College Laplace transform problems in order to protect my work at the university. I hope to get the highest score and get practice at the space station.

Kapusta

Oh, God it lives!!

Shoulda left this one in the grave.

Shimagnolo

Too bad it didn't arise just one day earlier.

seypat

Say it ain't so!

frogman

Exactly !!!