Bicycle efficiency enhancement

[UncleGary]

I'm not sure this is a new trick - it's so simple and effective, I'm surprised that I haven't heard of it before.

Bicycle Efficiency improved by cheap physics trick - The Fifth Force

-UncleGary

 

[alienator]

That doesn't change a bicycle's efficiency at all. It's got nothing to do with mechanical efficiency. Further, if you've been playing with physics, you know full well that "3 lbs" pushing down on the pedal doesn't arrive for free. In fact, by the Second Law of Thermodynamics, you have to do more work than the 3 lbs of additional downward force net you. So, efficiency isn't improved anywhere. What does happen is that the rider has to produce more power to go a given distance uphill than he or she would if they didn't have that additional 6 lbs of weight. This is obvious from an equation of motion for a bike. The predominant increased need for power is the result of the increased mass of the system (increases work required to increase elevation by a given increment; increases rolling resistance of tires; increases bearing friction). Too a much smaller extent, their power needs are increased by the additional moment of inertia of the two weights as they move around the bottom bracket.

As for any training benefit--improved strength, improved pedaling efficiency--you should read the ECSS-congress thread to see how improvements in pedaling efficiency don't necessarily follow the rules a person might think.

 

[frenchyge]

I'm not sure this is a new trick - it's so simple and effective, I'm surprised that I haven't heard of it before.

This is a joke, right?

 

[tafi]

Give me a break. Not sure whether to laugh or cry. I guess it could be funny if you negated the fact that some people take it seriously without thinking about it.

 

[UncleGary]

I suggest you try it before knocking it.
I agree that the efficiency of the bicycle is not improved (and in fact slightly degraded) However, the power output capacity of the body increases from the use of more muscles. It is the rider-bike combination that is enhanced.
I just had my 15 year old nephew try it and he's convinced. (If you've ever tried to convince a 15 year old boy of anything, that should be incentive to at least try it for 30 seconds.)

 

[Scotty_Dog]

If what you say is valid, why not add 30 pounds of weights to each leg? By adding only 3 pounds, it seems like you are limiting your true potential by tenfold.

Don't thank me when you win all of next year's grand tours, just send me a check. Err, make that a money order.

 

[frenchyge]

Better re-check your math Scotty, only 3 lb rotating masses can create the localized gravatational disruption which causes this to work so well. Besides, you'd probably pull a groin muscle trying to swing your leg over the bike, and that's no way to win a Grand Tour.

Instead, you should add weights to the pedals themselves rather than the ankles. That would provide the same physics-bending performance boost, wouldn't feel like you were dragging around dead cats when you stopped at the coffee shop, and would save a lot of money on those super-light pedals and shoes that most cyclists are falling for these days.

 

[alienator]

You guys are looking at this all wrong. Yeah, weights seem like the perfect solution, but on the downward stroke they're only making use of the standard, everyday acceleration of gravity. To really capitalize on this revolutionary idea, you need to use springs which cause a downward acceleration and exceleration. See F=ma=kx, so you only need to find springs with a spring constant, k=ηma/x, where η is any number greater than 1 and is the pedaling efficiency factor. So, if you want your pedaling to be 20 times more efficient than it is now, you need to buy springs with k=20ma/x, where x would be 2 times your crank length, m is the mass of the pedal/foot system, and a is your local acceleration of gravity. Obviously this will increase your acceleration, and by improving your efficiency, it thusly increases your exceleration (the rate at which your cycling increasingly excels).

Note: all claims herein are theoretical in nature and not a guarantee of actual results. No animals were harmed in testing, and all test subjects were monitored and observed using unobjective methods. Biomechanical claims are made without any knowledge of biomechanics whatsoever. All rights reserved.

 

[frenchyge]

Magnets might work well, too. You could probably use them to pull the pedal up, then reverse the polarity and make them push the pedal back down as well. At least that's what my neighbor's 6 yr old kid says. He doesn't like to try new foods, or new ideas in experimental propulsion, so there must be something to it.

 

[tafi]

Otherwise known as an electric motor....

 

[frenchyge]

Otherwise known as an electric motor....

But you'd attach a set of cranks to the magnets so you could flip them around by moving your feet in a circle, hmmm?

 

[alienator]

But you'd attach a set of cranks to the magnets so you could flip them around by moving your feet in a circle, hmmm?

So that you don't have to have onboard power to electrically flip the magnets' polarity, you can mount a lever on each ankle which, at the top and bottom of the pedal stroke, flips a spring loaded trigger that flips the magnet over, manually reversing the poles. The big benefit of magnets, however, is that being in such close proximity to the body, they will increase the rider's energy and vitality. As a side benefit, the magnets will prophylactically treat Magnetic Field Deficiency Syndrome.

I once put magnets on my dog. He seemed to run faster than he normally would and with much greater efficiency. I believe the magnets caused him to recruit muscles he didn't normally use, muscles that were obviously highly paramagnetic. I told him to bark twice if he felt like the magnets were ineffective, and he didn't bark at all. Test success. Hypothesis proven.

 

[tafi]

Right so you'd be putting force in (loss of efficiency) to turn the magnets over aginst magnetic forces and then use the same magnetic forces to help turn the canks round. You will never get out more than you put in.

The only real efficiency gain I can see is to use electromagnetic braking to charge a capacitor or battery and then use the energy generated to run a motor when you need extra acceleration. This is already done in some cars and trains.

 

[alienator]

Right so you'd be putting force in (loss of efficiency) to turn the magnets over aginst magnetic forces and then use the same magnetic forces to help turn the canks round. You will never get out more than you put in.

The only real efficiency gain I can see is to use electromagnetic braking to charge a capacitor or battery and then use the energy generated to run a motor when you need extra acceleration. This is already done in some cars and trains.

You know we're kidding, right?

 

[alienator]

An article was written once about a mechanical engineer in Youngstown, Ohio who had started his own company to develop an engine with an efficiency=1. He said in the article that at the time of the writing his engine's efficiency was only 0.1....but he was certain that he would achieve his goal. Uh-huh. Yes, he actually found people with money to back his project.

I love of science quackery. It's amazing what people can come up with when they ignore physical laws and scientific method....and avoid critical thought. There was another gent--an MD, I believe--who had claimed that he had come up with a theory of everything. You know, that means a nice unified theory of all forces, that extended from the quantum level to the macro world. The really "fun" part of his theory was that his theory allowed the quantum number, n, to have fractional values (In non-quack physics, n=1,2,3,.....). So in his theory, you'd have that quantum number being essentially 1/n where n is any number greater than 0. That'd be hoot and meant that when you're flash lamp energized your helium-neon laser--just once--that the laser would produce light forever because the electrons that had been pumped up in that helium-neon mixture would never reach their ground state. How cool is that: infinite energy from the flash of one lamp! Hell, it means you could get infinite energy out of a single atom of hydrogen. When questioned on the apparent problems with his theory, the quack switched to talking about applications of his theory. When questioned about the problems involved with applications of his theory, he switched to talking about his theory. Nice dance.

 

[64Paramount]

You guys are looking at this all wrong. Yeah, weights seem like the perfect solution, but on the downward stroke they're only making use of the standard, everyday acceleration of gravity. To really capitalize on this revolutionary idea, you need to use springs which cause a downward acceleration and exceleration. See F=ma=kx, so you only need to find springs with a spring constant, k=ηma/x, where η is any number greater than 1 and is the pedaling efficiency factor. So, if you want your pedaling to be 20 times more efficient than it is now, you need to buy springs with k=20ma/x, where x would be 2 times your crank length, m is the mass of the pedal/foot system, and a is your local acceleration of gravity. Obviously this will increase your acceleration, and by improving your efficiency, it thusly increases your exceleration (the rate at which your cycling increasingly excels).

Note: all claims herein are theoretical in nature and not a guarantee of actual results. No animals were harmed in testing, and all test subjects were monitored and observed using unobjective methods. Biomechanical claims are made without any knowledge of biomechanics whatsoever. All rights reserved.

Now all you need is the ghost of Billy Mays to hawk it for you on late night TV for $19.95 plus S/H.....

 

[swampy1970]

Magnets might work well, too. You could probably use them to pull the pedal up, then reverse the polarity and make them push the pedal back down as well. At least that's what my neighbor's 6 yr old kid says. He doesn't like to try new foods, or new ideas in experimental propulsion, so there must be something to it.

Magnets won't work - depending on the orientation they'll only pull you towards either magnetic north or south. Try telling the marshall at the turnaround of a time trial that you're not cheating but just realigning your magnetic foogenhazen whilst in reality your moral compass is way out of whack...

Michael Jackson apparently got kids to try 'stuff' - doesn't mean that I wanna play 'hide the bleached twinky'

 

[billydonn]

It's posts like this one that make this forum invaluable!

 

[alienator]

Like a loveless marriage, you have to wonder where the attraction is:

 

[frenchyge]

Like the repulsive force between poles at a sausage fest.