Naked Science Forum
General Science => General Science => Topic started by: Matt McKee on 17/04/2009 11:30:02
-
Matt McKee asked the Naked Scientists:
Some of my old A-level physics students discussed "could you balance upright on a stationary bike without a stand?"
It led to some great ideas about centre of gravity and size of contact areas but we couldn't decide - consensus seemed to be in theory yes, in practice, no, not without lots of wobbling and adjustment.
What do you think?
-
Circus acts have been doing this sort of thing for years. I suppose its a matter of balance awareness. I couldn't do it.
-
I imagine it is very possible to do so, with little wobbling.
Maybe not so related: http://www.pedalmagic.com/Physics.htm
-
Many people, who use a bicycle frequently, can balance without putting their feet down, and without much wobbling about. It's a very common ability amongst competitive cyclists, who will have their feet/shoes locked in to the pedals and want to avoid having to disengage them.
The Guiness Book of Records used to have a category for the slowest bicyclist, but it was abandoned after one person managed not to move at all during the entire duration alloted to the task, achieving a measured speed of 0.
Have a look at:
http://en.wikipedia.org/wiki/Track_stand (http://en.wikipedia.org/wiki/Track_stand)
-
When I was a teenager I played for a while "Radball" (cycleball). It is played in teams of two and you spend a lot of time standing still without being allowed to touch the ground with a foot. Or go backwards. Or whatever. Fact is, the bikes have a 1:1 gear ration with fixed gears, so you can pedal and move backwards. You turn the front wheel and balance left to right by pedaling front and back just a bit. That part of the game was easy. The rest incredibly hard.
See:
And, as LeeE said, in track cycling they do it too. Same method, but different gear ratio:
(at minute 3:40 they stand still for a while, shortly after they go over 60 km/h)
-
Thanks, some really interesting and helpful replies [;D]. In true teacher fashion though it's been pointed out to me by one of the more astute students that the original question was based on there not being a rider, i.e. the bike on its own, so my mistake [B)] for not being clearer; consider this the extension task [:D]
-
I don't see how that is possible.
-
I think all depends on the rake of the forks.
When I get on the rollers, people are amazed that I don't fall over. (It amazes me sometimes as well)
-
See what can be done (with a bit of practice) here...
http://theridiculant.metro.co.uk/2009/04/cycling-through-edinburgh-the-extreme-version.html
-
WOW! [:o][:o][:o][:o]
That bike must have really really really good suspension.
-
WOW! [:o][:o][:o][:o]
That bike must have really really really good suspension.
I think it's called "Thigh muscles"...
-
Did you see the way that bike was landing?!?!
Of course, you've got to have strong muscles everywhere to do that but if he tried in on my bike he'll be going to the hospital in a matter of seconds!
-
Silly me - wrong video.
No amount of suspension is enough - I think these people have rubber knees.
-
Huh? What video were you watching? There was only one! [:)]
-
Karsten's track sprinting one a few posts up. Didn't notice that another one had been posted since!
-
Pretty neat the Edinburgh video. I don't know what else this person can do well, but he sure can do this well. Although I would not be surprised to hear about a fatal accident when trying almost any of what is shown. A little Styrofoam helmet can do only this much. I would like to see a list of injuries he accumulated in his "career".
I think it's called "Thigh muscles"...
I would not be surprised to learn that holding onto the handle bar while landing allows you to use your upper body muscles to help with landing. It may not all be thigh muscles. But I have never tried (nor hope to ever will). Good thing the seat is installed rather low though.
-
In true teacher fashion though it's been pointed out to me by one of the more astute students that the original question was based on there not being a rider, i.e. the bike on its own, so my mistake for not being clearer; consider this the extension task
If you take off the tires and tubes you can place your bike on the rims (which are now sitting with the two edges touching the ground). If you do this on a hard, level surface you can probably balance the bike like this. Or you stick it in thick mud. Hard surface but with inflated tires only- I doubt it. Theoretically maybe but not practically. Any vehicle driving by would disturb the bike so much it would tip. Any draft of air would do the same. And there are so many more things to do than to waste months trying.