Airless wheels for mountain bikes may ditch patches and pumps (w/ Video)

Nov 04, 2012 by Nancy Owano report

(Phys.org)—A Colorado company sees the future of tires on mountain bikes, and they are puncture-proof and airless. Britek Tire and Rubber also envisions mountain-bike riders as being in a far happier mood when they learn they can leave their patch kits and pumps at home. For several years the company has focused its prototyping efforts toward airless tires for automobiles but it is now turning its attention to working on airless tires for mountain bikes. Company founder and designer Brian Russell has several patents and more pending for his dream project, the Energy Return Wheel (ERW). In addition to not having to worry about punctures, he says people will find that ERW can deliver better efficiency.

"The ERW is not a competitor to hybrid, electric, hydrogen, ethanol, biodiesel and other fuel saving technologies," according to the company. "Quite the contrary, because it will only make vehicles using these technologies more efficient."

The company has been around since 2002 with a goal "to reinvent the wheel." Russell explained why he calls his concept "Energy Return Wheel." He said that the physics behind the ERW is like that of a garage door.

This video is not supported by your browser at this time.

"Even though a garage door weighs several hundred pounds, when it is sprung by the use of springs, it becomes de-weighted. So when you lift it, it only feels like it weighs a few pounds. In summary, an object that is sprung requires dramatically less energy to move than an unsprung object. In addition to the use of springs, an object can be sprung by stretching rubber. Scientists call this "Elastic Potential Energy."

At the center of the ERW is a layer of rubber. Via rods that are adjustable, the rubber is stretched, which stores elastic potential energy in the . He said the ERW thereby is turned into "a 360-degree slingshot that retains energy."

This video is not supported by your browser at this time.

When the ERW is attached to an object, that object becomes sprung. "Just like a garage door that is sprung, the attached object becomes de-weighted and requires dramatically less energy to move than an unsprung object. Less to move means an increase in fuel efficiency."

A car riding on his wheels would be "like riding on four slingshots," according to the designer. The Slingshot Effect could improve acceleration, and since the wheels could de-weight the car, he said, the rider would also see improvements in braking performance.

He also promoted the ERW's inner elastic layer construct, which provides the cushioning that air provides in traditional tires. He said that initial tests show that the elastic layer takes away vibration.

According to the company site, Britek Tire and Rubber is looking for sponsors and companies wanting to license its product in the United States.

Explore further: Amazon worker piloted drone around Space Needle

More information: www.energyreturnwheel.com/Home.aspx

Related Stories

Bridgestone goes airless in tire concept for Tokyo show

Dec 03, 2011

(PhysOrg.com) -- Visitors to the 42nd Tokyo Motor Show are to witness a new breed of airless tires from Bridgestone. Interest in the general press is already humming because of the material, design, and features ...

A new genre of tires: Call 'em 'sweet' and 'green'

Dec 14, 2011

Motorists may be driving on the world's first "green" tires within the next few years, as partnerships between tire companies and biotechnology firms make it possible to produce key raw materials for tires from sugar rather ...

Japan demo shows electricity entering EV through tires

Jul 08, 2012

(Phys.org) -- Electric vehicles' future continues to tease scientists to devise promising and practical ideas to keep these cars moving along the highways without having to pull over and wait for a battery ...

Scrap tires can be used to filter wastewater

Nov 17, 2006

Every year, the United State produces millions of scrap tires that clog landfills and become breeding areas for pests. Finding adequate uses for castoff tires is a continuing challenge and illegal dumping has become a serious ...

Recommended for you

Hoverbike drone project for air transport takes off

Jul 24, 2014

What happens when you cross a helicopter with a motorbike? The crew at Malloy Aeronautics has been focused on a viable answer and has launched a crowdfunding campaign to support its Hoverbike project, "The ...

Student develops filter for clean water around the world

Jul 23, 2014

Roughly 780 million people around the world have no access to clean drinking water. According to the World Health Organization (WHO), 3.4 million people die from water-related diseases every year. ETH student Jeremy Nussbaumer ...

User comments : 20

Adjust slider to filter visible comments by rank

Display comments: newest first

MrVibrating
2.4 / 5 (7) Nov 04, 2012
Driving on balloons is nuts, yet they also have obvious advantages, so i've been following the progress of non-pneumatic tyres for some time... the idea's not new.

I'm unconvinced however by the supposed novelty of the 'energy return' principle here - surely this was the whole point of pneumatics in the first place? If i understand correctly that the elastic PE here is in tension, as opposed to compression per air-filled tyres, this has no bearing on the outcome of the effect - it doesn't flip the sign of the elasticity; it's still a taut circle. Instead of the tyre deforming, the wheel position flexes within the tyre, but it's still just a form of suspension.

Puncture immunity is of course desirable, but then so is the ability to vary the elasticity by changing the air pressure, which this design doesn't appear to address.

For now, i think a better redesign for bicycles would be tubeless tyres as found in cars and most motorcycles. Much easier to plug on the fly..
Klewch
4.2 / 5 (5) Nov 04, 2012
Rotational weight is a killer on a bike and these look heavy.

Tubeless tires are available now I ran them a few years ago, they are finicky, think spokes through the rim, dirt on your sealing surfaces and trying to run lower pressures for grip. I went back to tubes, there cheap and they work.
Klewch
3 / 5 (2) Nov 04, 2012
Any idea where in Colorado that video is shot? They look like they have a terrible Venison infestation.
antialias_physorg
not rated yet Nov 04, 2012
the idea's not new

True. Check this out (this is from post WWII germany where rubber was in short supply. Simple, effective and probably a damn sight better on icy roads than rubber tires)
http://www.fotoco...20253407

I went back to tubes, there cheap and they work.

Yes. Some years ago I switched to kevlar reinforced treads. haven't had a flat ever since.

Rotational weight is a killer on a bike and these look heavy.

I can see the invention being pretty useful for the hardcore mountainbike crowd (as noted in the article). Rotational weight is of very little concern when you seriously go off-road.

But for those of us who ride mainly on (dirt) roads the air filled ones work just fine. And for the high-speed crowd there are already airless rubber rims available.
BikeToAustralia
5 / 5 (1) Nov 04, 2012
Several people told me airless foam-filled tires roll off the rim. Michelin was working several years ago on "S" shaped spring steel spring wheels for cars instead of the trapezoidal springs shown here.

Durable tires is essential for epic bike touring. (Kevlar endorsement noted) Mechanical failure is inevitable. ("BikeToAustralia" is one word on the internet).

These airless tires look as though they would catch twigs and rocks in between the wheel and the rim. I would expect to see (brightly coloured, flashy) screening preventing that. But, obviously, these tires have been (off-)road tested for a long time. Oh, wise ones with the hands on experience, what prevents debris from getting in the holes?

@Klewch
Any idea where in Colorado that video is shot? They look like they have a terrible Venison infestation.
- Funny
elektron
1.8 / 5 (5) Nov 04, 2012
A garage door is rendered 'weightless' by springs attached to a fixed object (the frame) I do not see how it is in any way analogous to tires being 'sprung'.
Jeddy_Mctedder
1 / 5 (4) Nov 04, 2012
this idea has been tried so many times. never works. i know people whove tried bike tweels and hated them. that said....
i wish this attempt good luck!
Lex Talonis
1 / 5 (4) Nov 05, 2012
Yeah send me a set and I will thrash them and tell you if they are any good.

If not... don't worry.
c0y0te
1 / 5 (1) Nov 05, 2012
Won't mud fill up those holes?
Mike_Massen
2 / 5 (4) Nov 05, 2012
The bulk of any sorts of dross will be flung out pretty quickly...

By way of comparison, I've been running twin tyres on a regular automotive sedan and people occasionally claim stones will get stuck, the forces however are against that rather significantly and in the 2 decades or so I've not had a problem including on rough country roads.
Doug_Huffman
1 / 5 (2) Nov 05, 2012
These are solutions in search of a problem and a product in search of a market. Capitalism functions well only in an educated and skeptical market.

My experience is that p*nct*re rate is correlated with tire weight. Momentum, be it linear or rotational, is conserved.
antialias_physorg
not rated yet Nov 05, 2012
Won't mud fill up those holes?

If you're riding the kind of terrain where punctures are a real issue then a bit of mud is the least of your problems. At that point you have mud all over you and hanging off in clumps under your shoes, anyhow.

And at any speed above walking pace I wouldn't expect it to stay in there for long.

Cleaning the bike might be more of a bitch than usual (but at those levels of activity you probably do have access to a garden hose or similar)
dschlink
5 / 5 (1) Nov 05, 2012
I'm guessing that the mud question was targeted at the energy-recovery feature. If you have to squeeze mud out of the tire with every rotation, it would be a real energy drain and make the rotational weight much higher.
TheGhostofOtto1923
3.8 / 5 (13) Nov 06, 2012
The bulk of any sorts of dross will be flung out pretty quickly...
Uh no it wouldnt.
If you're riding the kind of terrain where punctures are a real issue then a bit of mud is the least of your problems.
No it would be significant. With each rotation, rocks and dried mud would affect your ride and your handling. And it would add to rotational weight which is the most critical weight on a bicycle. These tires already look MUCH heavier than regular tires.

I assume that the manufacturer would want some sort of fabric sidewalls but I imagine these would wear out quickly no matter what they are made of, especially on a mt bike.
TheGhostofOtto1923
3.8 / 5 (13) Nov 06, 2012
I see klewtch already mentioned rotational weight. Anyone who has powered up more than a few wet, rocky, rutty hills can tell you that weight and handling are huge considerations.

Downhillers might be the only ones to use this gadget.
He said the ERW thereby is turned into "a 360-degree slingshot that retains energy."
You mean like those running shoes with the springs in the heels that they sell in the back of Popular Mechanics mag?
packrat
1 / 5 (3) Nov 10, 2012
I use the no flat tubes on my recumbent trikes and stuff at home and will never go back to air filled tubes. The foam tubes are heavier but not having to worry about flats anymore is worth it to me.
I would really like to try a set of these if I could get them installed on the plastic type mag wheels. The only real problem I see is replacing them once the tread wears out. On some plastic mag wheels these would be pretty indestructible on most kids bikes. Not as light as a good racing wheel but no flat tire maintenance worries for dad either...
GaryB
5 / 5 (2) Nov 10, 2012
From a business point of view, I'd shy away from trying to compete with a widespread cheap solution that works pretty well already (tires). As stated above, kevlar reinforced treads minimize flats already. I'd try these however just to see.

I think there's a new category of bike: down town get-around that's made really solid and simple that you almost never have to maintain and isn't meant to be optimal. This would be perfect for that -- no flats. Add a touch of electric assist and you'd ride like a high end road bike but no maintenance. That's the market I'd go for.
Mike_Massen
2 / 5 (4) Nov 11, 2012
TheGhostofOtto1923 needs meds again with
When I said
The bulk of any sorts of dross will be flung out pretty quickly.
Uh no it wouldnt.
Huh ! Yet you didnt explain why, Are you under the impression there is NO axial acceleration component ?

Check your basic physics please !

If you say it "wouldn't" please explain why YOU feel it wont, that should be easy for you instead of insulting me yet again or referring to my hair as an immature means to attack !

TheGhostofOtto1923 mumbled
I assume that the manufacturer would want some sort of fabric sidewalls
Why assume, where is your logic, production engineering etc, some basis to a whim rather than lazy assumption ?

TheGhostofOtto1923 mumbled more
I see klewtch already mentioned rotational weight. Anyone who has powered up more than a few wet, rocky, rutty hills..
Are you also under the impression a wet/muddy tyre takes on a lot of weight, it doesnt as movement takes most off, I know, I bike ride a lot, do you ever ?
TheGhostofOtto1923
3.8 / 5 (13) Nov 11, 2012
Huh ! Yet you didnt explain why, Are you under the impression there is NO axial acceleration component ?
Why would you think I was under that particular impression? And why do you think there might be enough 'axial acceleration' to clear these wheels of crap between the time they pick it up during rotation and the time where it would disrupt compression and affect handling?
Are you also under the impression a wet/muddy tyre takes on a lot of weight, it doesnt as movement takes most off, I know, I bike ride a lot, do you ever ?
I assume that THESE tires may take on enough to affect ride and handling on a tough hill climb as well as the descent. I anticipate problems with new tech whereas you assume none. Why is that? I also assume you haven't read the thread as you didn't know that I have ridden a lot.

I also assume that you put spaces between letters and punctuation because you think it's cool or because of some neurotic disorder? COPD?
TheGhostofOtto1923
3.8 / 5 (13) Nov 11, 2012
Forgive me, OCD. I know it is unfair to make fun of the afflicted, but it is useful in making a point.