Assuming it isn't fake of course.
litmotors.com/
Want one!
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Gyroscopes.
Notice it didn't show going round a bend, probably don't need the gyros once it's running above a few MPH.
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Gyroscopes are cool.
Very.
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Gyroscopic effects have NOTHING to do with bicycles staying upright.
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>> Gyroscopic effects have NOTHING to do with bicycles staying upright.
I understood it was the gyroscopic effect of the wheels rotating that played a part in keeping bikes upright. Hence race teams often fit lighter wheels to motorcycles, not only for unsprung weight savings, but also to make the bike easier / quicker to tip into a turn.
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According to this the effect is only significant on motorbikes:
hyperphysics.phy-astr.gsu.edu/hbase/mechanics/bicycle.html
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Maybe the effects are small in comparison with a hefty m/bike wheel, but just spin a bike wheel whilst holding it by the spindle, and tilt. It will strongly resist deviation from it's current alignment.
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Nothing new under the sun Ted !
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I've got a photo of the gyrocar too in the Wonder Book of Why and What, already 25 years out of date before I got it as a child but much treasured for many years.
It was obvious to me even as a child that the thing couldn't work properly and had no purpose. Funny though.
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>> www2.eng.cam.ac.uk/~hemh/gyrobike.htm
>>
>> All the debunking you need is here.
Slight contradiction with your emphatic assertion that "Gyroscopic effects have NOTHING to do with bicycles staying upright", in that in the link it says "The gyroscopic effect helps" and "the gyroscopic effect is small"?
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>> Slight contradiction with your emphatic assertion that "Gyroscopic effects have NOTHING to do with bicycles
>> staying upright", in that in the link it says "The gyroscopic effect helps" and "the
>> gyroscopic effect is small"?
Recently serviced the front wheel on my older Brompton. Just twirled at low speed to get the adjusment tickety boo the gyro efffect in the tiny 16inch wheel was very evident. Whether it helps keep shiny side up I cannot say.
Last edited by: Bromptonaut on Tue 12 Jun 12 at 11:02
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>> Gyroscopic effects have NOTHING to do with bicycles staying upright.
>>
True. The same way a stunt driver can balance a car on two wheels - by steering "under" the side it want's to fall over to.
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Pfft. Jump off a bike doing 15mph and watch it continue onwards for many seconds before it topples - do the same at 1mph and it'll fall right over.
Must be magic /rolleyes.
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I'll have to remember that Lygonos.
The reason I was doing 120mph your Honour was to keep the bike upright. It's yer gyroscopic effect init, any slower and it would simply topple over after a few metres. :-)
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>> Pfft. Jump off a bike doing 15mph and watch it continue onwards for many seconds
>> before it topples - do the same at 1mph and it'll fall right over.
>>
>> Must be magic /rolleyes.
>>
If you have an equivalent wheel rotating in the opposite direction to the first wheel, then there is zero gyroscopic effect. See my link above.
/rollseyes .
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You stated there is NO gyroscopic effect in stabilising a bicycle.
Are you correct?
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Lygonos wrote:
>> You stated there is NO gyroscopic effect in stabilising a bicycle.
>>
>> Are you correct?
Let's address whether the statement contained in the latter nine words of your first sentence is correct, rather than answer your question. I think one could just about argue that the above statement implies the correct answer, but I think that one could equally argue - as you suggest - that it is strictly incorrect.
Now, let's see whether there is any truth at all in your first sentence. What I actually wrote was:
>>Gyroscopic effects have NOTHING to do with bicycles staying upright
Which is true. It is the rider that keeps the bicycle upright. There may well be a small gyroscopic effect arising from a bicycle wheel, but take it away completely (see my link) and the bicycle remains upright. Therefore bicycles stay upright independent of any gyroscopic effect and therefore my statement is correct, but the wording you associate with me is not.
what is so clear is that it really makes no difference to the "ride" of the bike. The bike is just as easy to ride whether the extra wheel is spinning or not, forwards or backwards, fast or slow.
/rollseyes Please take more care when quoting other posters in future. There is a convenient "quote original message" button which should make it easier for you not to put words into somebody else's mouth.
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>>Gyroscopic effects have NOTHING to do with bicycles staying upright.
"Nothing" - not anything.
They have no effect whatsoever in facilitiating the upright position of a bicycle?
Zero?
I'd suggest they have SOME effect which implies your statement is wrong.
Unless mine is wrong.
It is not necessary for there to be any gyroscopic effect to keep a bike upright: I can keep a bike upright almost indefinitely without the wheels rotating by moving my weight/tweaking the handlebars/hopping the wheels.
Why does a riderless bike take longer (time, not just distance) to topple when it is going faster?
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>> Why does a riderless bike take longer (time, not just distance) to topple when it is going faster?
Other than the tendency of a bike with decent fork geometry to turn into the fall of course ;-)
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>> Pfft. Jump off a bike doing 15mph and watch it continue onwards for many seconds
>> before it topples - do the same at 1mph and it'll fall right over.
>>
That's momentum, not gyroscopic action. Push a drunken man out of a pub and he will totter for a few yards before falling over.
The gyroscopic theory of bike balancing requires there to be a rider. Sensing that the bike is leaning, he turns the handlebars, and the gyroscopic force from the rotating wheel pushes the bike back upright.
No one is disputing there is an effect, but it is very slight and is not the reason people can balance bicycles. An expert can balance a stationary bike.
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Forward momentum alone does not impart stability around the longitudinal axis.
Why do you think bullets don't go straight unless you impart spin?
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You are absolutely right - a bike remains upright because of the rider constantly turning the handlebars to and fro but to say there is NO gyroscopic effect is nonsense.
With powerful enough gyroscopes (plus a little control) a bike can be kept upright - that's what stops a Segway falling over when it's stationary.
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Supplementary question please, which may or may not be related to the above discussion and theories postulated on gyroscopic effects...I'm not nearly clever enough to venture an opinion on the science of that but I do know that the faster my bike is going the more stable it feels. Same on skis though to be fair and they don't spin unless you're really in trouble...
Why is a bike with small wheels less stable at any speed ( or feels it anyway ) than one with big wheels? Same effect can be felt on a motor scooter versus a motorbike too can't it?
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I'm not really into football so I may just go out t't shed with a bike wheel, a cup hook and some string... Why do I feel a trip to A&E coming on?
:-)
Last edited by: Humph D'Bout on Tue 12 Jun 12 at 21:19
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Wow. The motoring equivalent of a Weeble.
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>> Why is a bike with small wheels less stable at any speed ( or feels
>> it anyway ) than one with big wheels? Same effect can be felt on a
>> motor scooter versus a motorbike too can't it?
Difficult Q Humph.
Treating this as a science experiment you'd only change one thing at once. Yet pretty well all small wheel bikes also have different frames. Usually a single oval or tube rather than a 'triangle' between the headset and seat tube/bottom bracket. All too often the frame is a compromise for compact dimensions and/or a cheap route to foldability.
The Brompton is certainly 'twitchy' unladen but with a pannier on the headstock it calms down considerably. That's a function of it's design. Won't take mine down the local 1:10 quite as fast as I would the Dawes Galaxy but that probably owes more to braking capacity than stability.
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>> that the faster my bike is going the more stable it feels
Yes, that's very much in evidence if you are riding one bike and pushing another along by the saddle - it's quite awkward to get going but much easier once at a moderate to high speed.
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The link posted by MM above is quite correct. Gyroscopic action is not necessary to enable a bike to balance.
The rotating wheels will provide some gyroscopic stiffness, however, this is a small effect.
When we hold a wheel in our hands, the effect might feel strong, but, as we hold the axle, the moment arm is small, i.e., the distance between the points where the wheel is held are close together, so, even a small moment is difficult to react by hand.
Small wheels will have small trail, and hence one of the mechanisms of self-correction is diminished.
As balance on a bike is an averaging process, where the amount of error to the left must equal the amount of error to the right in a time averaged sense, it takes larger deviations from equilibrium to correct at low speeds - hence it's more difficult to remain stable at low speeds.
So, the gyroscopic effects may help, BUT, they are not necessary, and they are not the dominant reason or explanation why bikes can be balanced.
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It looks fake, virtually all the shots are close medium shots.
For example, when the bike is towed sideways why crop the top and show so much floor? Hiding a bungy or boom?
If towing this bike sideways, you would need more than gyroscopes to keep it upright.
It would have to grossly and quickly shift it's centre of gravity, and in this case that would require shifting mass outside of the vehicle's body-space.
Last edited by: sooty tailpipes on Wed 13 Jun 12 at 11:04
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Self balancing bike. Amazing. - bathtub tom
