/sci/ - Science & Math

>>988902
He's right, because they are "hooks" that hold the wheel, but i've known this since 1982.

........?

>>988894
I know, I cleaned and reassembled my back wheel and gearbox last week.

ORLY?

>>988894

No shit Sherlock

Figure that out all by yourself?

>>988907
>>988894
So the spokes don't connect from the rim to the center. But rather, they connect from one side of the rim to the other, kinda like this?

>>988930
No compressive strength, only tensile strength

so, if the hooks were inverted....THEN, you'd have the wheel supporting the bike from below?

pic related

>>988931
They hook directly onto the hub

>>988931
Actually now that I look at it, the loops are a lot tighter than what I have drawn. But still, the same principle applies.

>>988938

/thread

Good, now figure out how it keeps the bike from falling over to the side.

>>988949
If I'm not mistaken, inertia from the spinning wheel takes care of that.

>>988955

Ya its gyroscopically stable.

>>988955
>>988959
Nope.
Try again.

Hint: it has to do with faggots using it.

>>988982
I'd like you to show me how to stay upright with a bike when it's stationary.

>>988982
>Nope.
>implying bikes don't stay upright when you push them

>>988985
>>988987
2nd Hint: You can't drive a bike in a straight line, no matter how hard you try.

>>988982
>>988998
What the fuck are you up to?

http://www.youtube.com/watch?v=8H98BgRzpOM

>>988998
the curvature of the earth

>>988998

Because the earth is round, and orbiting the sun & the sun is orbiting the milkyway?

>>988998
If you are fast enough, you can.
learn2bike

>>989005
Holy shit, that's awesome

In that case, the wheel should collapse as soon as the wheel slows down.

>>989024
How so, science fan?

>>989005
The gyroscopic effect isn't enough unless you are going fucking fast. Instead people will turn to the side they are leaning to. One would think you faggots knew this already.

>>989026
OP's pic seems to be implying that the connections from the wheel to the axis are supple, not rigid, in which case centripetal acceleration should be the only thing pushing the wheel into a circle.

>>989047
that post gave me cancer

>>989047
The connections are supple, the axis basically hangs off the rigid outer wheel

>>989047

Yes the over simplified explanation doesn't cover the finer nuances but only the general idea. Well spotted.

>>989057
I can't see how it fits the general idea at all. Just because the end connections are composed of hooks rather than bolts or welding...

the gyro effect is insignificant on bikes, although newfags say it is why bikes are inherently stable while moving. i never understood why they think this though, it was obvious to me when I first learned to ride a bike when i was like 5 years old what was causing it to become stable at speed.

its because the pivot axis of the steering is angled and if you drew a line it would contact the ground IN FRONT of the front tire, which causes the bike to automagically want to steer in a straight line. also makes the bike steer under you when you lean etc.

>>989056

Oh, I see. Disregard

>>989057
>>989047
and
>>989024

I never learned how to ride a bike. How do you get started?

>>989124
Yeah, it's funny how people will find more complicated ways to explain stuff when the answer is simple and intuitive.

When I want to turn left, I lean left first.
When I want to go straight, but I'm leaning left, I turn left a little bit.

The picture is false.
>What you think is happening
Nope, I know about tension.

The bike WANTS to be upright thanks to the spinning wheels. More wheel spin, more stability. A motorbike going 300 mph is a hell of alot more stable than people seem to think.

ITT: nerds who think reality are made of ideal cases

Both are happening at the same time, with emphasis on tension.

op is a fag

I think that the force is distributed over all of the top spokes, with the relative force per spoke roughly equal to cosine of the angle from straight up.

>>989124
your explanetiong makes no sense.

its the gyro thing

>>989219
How does gyroscopic effect work at walking pace?

How does one ride a bicycle at walking pace?

>>989212

no.

there is no compression. with no load on the wheel there is maybe 50 pounds of tension per spoke, it would take many hundreds of pounds before there could be compressive forces on any spokes and the wheel would then fail because the spokes are only hooked in and cannot support any weight at all that way.

>>989230
why is it so difficult to ride a bike on slow speeds?

You have to count on your equilibrium only

bikes are supported by tensile forces.
bikes are stable because of gyroscopic forces.
/thread.

Unrelated to push bikes but still relevant. When I started riding motorbikes I would try to lean the bike over as far as I could while going in a straight line. With counter steering I could get the bike up to 30deg. off center. This is either gyro effect or magic.

When you turn the wheel to the left, the direction of the bike begins to turn to the left. The weight of the bike (and you) still try to continue on in the same direction (CENTRIFUGAL FORCE), which of course tilts the bike to the right because your momentum is carrying you off to the right side relative to the direction of the bike.

Thus, if you're falling left, you instinctively turn the wheel slightly left to compensate, and you make this adjustments constantly. It has nothing to do with the wheels acting as gyroscopes.

>>989257
For an ideal bike yes.

But I'm willing to bet 100 000 000 000 bazillion dollars on that if you put an accurate meter to the task you would measure compression.

Only think it takes is for one of the spokes to be fitted a bit more snugly than the rest into the hook hole and you'll get compresison on it.

>>989286
If you tilt the bike over without compensating by leaning your weight toward the center of gravity, you're going to fall over, unless you're going pretty damn fast.

>>989329
yeah I did have to lean and keep myself vertical while the bike was over.
  |
/

>>989357
yeah, that isn't a gyroscopic effect. pic related.

>>989314
I would like to disagree.

>Steering a motorcycle or bicycle is counterintuitive; to turn right, you must steer left initially, and
vice versa. You can execute this initially counter-directed turn by turning the handlebars explicitly
called counter-steering or by throwing your hips to the side. Contrary to common belief,
gyroscopic forces play only a limited role in balancing and steering

http://docs.google.com/viewer?url=http%3A%2F%2Fsocrates.berkeley.edu%2F~fajans%2Fpub%2Fpdffiles%2FSt
eerBikeAJP.PDF

>>989400
Again, pic related

>>989413
I don't see how that contradicts anything I said.

I ride my bike most of the time without touching the handle bars. I move my knee in the direction i want to go for small turns and lean into the turn for big turns. Please tell me you aren't so retarded as to think this is anything other than gyroscopic effect. I understand it isn't that the gyroscopic effect rigidly holds the bike upright, but rather corrects for tilts by turning the wheel the appropriate direction. Are you retarded /sci/? please say no.

>>989469
placebo effect. gyro's only a theory. tension.

centripital acceleration is the answer since you are also getting new friction all the time

>>989503
confirmed for retarded, troll, or jokester.

>>988928
this

To the people who are claiming that the gyroscopic effect is responsible for your bicycle's stability, I am severely disappoint. You are either trolling or incredibly stupid. Either way, leave /sci/ forever.

>>989591
explain plz, with citations.

>>989605
Not that dude, but it was demonstrated that the gyroscopic effect is negligible. It is the angle of the front fork that matters.

>>989459
Then you are fucking blind, it clearly says that gyroscopic effects are actively trying to tip the bicycle over or make it drive into a ditch.

>>989591
Samefuckingfag

When the center of mass begins to lean to the left, the wheel must be turned to the left to balance it. Inertia is was fucking keeps it up.

If this is too hard to imagine for you fucking dolts, imagine balancing a meter stick (or a yard stick for my fellow retarded americunts) on your finger. If it leans to the left, which way should you move your fucking hand to keep it up? GYROSCOPES?

>>989644
And yes, I am well aware that I have been trolled and trolled hard.

>>989644
So when I ride my bike at a fairly brisk pace and I lean about 50 pounds of weight to the left while I keep the front wheel straight and I don't fall over. What's keeping me upright? Magic?

>>989657
>50 pounds of weight to the left while I keep the front wheel straight and I don't fall over

You are either
1) Subconsciously making adjustments to your direction by steering and countering the fall
2) Leaning the bike in the opposite direction so the center of mass is still... centered
3) Falling

There is no magic and the gyroscopic effect is negligible at reasonable speeds.

>>989657
What short of lean are you talking about?
Try doing that lean when you are stationary or moving very slowly, if it's impossible, we'll talk.
Maybe you are turning to the left to stop it from falling over?