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ZeroLengthCurve  
#1 Posted : Wednesday, May 7, 2014 6:14:17 PM(UTC)
ZeroLengthCurve

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http://www.wired.com/2014/05/an...r-bikes-and-wheelchairs/

This is one of those "****DAMN****, I wish ***I'D*** thought of that!" moments.

" SoftWheel addresses this problem with their symmetric and selective technology, that uses three compression cylinders to absorb shocks within the wheel before they™re transferred to rider. The goal is to make the wheel™s hub essentially float in mid-air while suspending the chair™s mass. Practically this means riders can traverse stairs and curbs nearly as easily as gliding down a ramp by allowing the wheels to bear the brunt of the forces. Once you™ve eliminated sagging and bobbing you can work miracles, says Barel.

SoftWheel is novel, it™s also backwards compatible and has applications in other product categories, like bicycles. We bought off-the-shelf bicycles and within 10 minutes we put SoftWheels on them; it was just plug and play, says Barel. This modular aspect of the design also makes switching out wheels relatively simple, a fact that has attracted interest in a number of industrial and aeronautic applications. "
zumer  
#2 Posted : Wednesday, May 7, 2014 10:40:26 PM(UTC)
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Some of the blurb doesn't gel. If the shock is "absorbed" in compression cylinders, energy is dissipated as heat. A rigid wheel doesn't do that, the accompanying claim that more energy's lost through spoked wheels doesn't ring true. I'm willing to accept that a rigid chair fatigues the user more, and that going downstairs like in the vid might be easier than with spoked wheels (although spoked or cylindered, I'd wager that not many paraplegics are going to be doing it without thinking twice), but, energy-wise, unless there's an energy recovery function (like the Copenhagen wheel that's mentioned in the article), it's not more mechanically efficient than a conventional wheel. It's heavier, and more expensive, too. I'm not convinced.
ZeroLengthCurve  
#3 Posted : Sunday, May 11, 2014 10:15:12 PM(UTC)
ZeroLengthCurve

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Maybe they wheels' shocks have accelerometers and gyros in them? :) :) :)
ZeroLengthCurve  
#4 Posted : Sunday, May 18, 2014 12:46:46 PM(UTC)
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Say, Zoomer,

Here's how I see it:

The wheel is, as you say, solid. But, that's the rim of the wheel. Imagine bushing in the center, attached to rigid, ring, and the bushing has great springiness.

With the rubber band attached, and a shaft or weight mounted to two opposite wheels/rims, the weight on the shaft will stretch the band affixed to the spokes' common center.

I see the rider being given a smoother ride.

The shock-absorber arrangement seems to have linkages at the hub to the shaft. They'd need the wheel to be rigid so the links can stay attached to the rod between the two wheels.

I wonder whether their patent covers 4, 5, and 6 rods/tie rods/shock absorbers.
zumer  
#5 Posted : Monday, May 19, 2014 3:24:21 AM(UTC)
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The giveaway's in the term 'shock absorber'. Shock is energy input to the system. If it can be recovered, it can be used. If it can't, it hasn't been 'absorbed', it's been dissipated, damped, wasted. And it's heavier, which gets worse with more pieces.
ZeroLengthCurve  
#6 Posted : Thursday, May 29, 2014 9:39:14 AM(UTC)
ZeroLengthCurve

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Originally Posted by: zumer Go to Quoted Post
The giveaway's in the term 'shock absorber'. Shock is energy input to the system. If it can be recovered, it can be used. If it can't, it hasn't been 'absorbed', it's been dissipated, damped, wasted. And it's heavier, which gets worse with more pieces.


Thanks for the clarification, Zumer. I forgot/hadn't considered that.
Christinetran91  
#7 Posted : Monday, October 6, 2014 9:39:27 PM(UTC)
Christinetran91

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Viet Nam

Maybe they wheels' shocks have accelerometers and gyros in them?
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