Airless Tire at last on bikes first!

[Nicolas]

I'm pretty excited to hear about a partnership between Bridgestone Corporation and Bridgestone Cycle, which is introducing an airless tire made from recyclable resin. It's been a long time in the making and I had heard nothing for the past 5 years.

http://www.bridgestone.com/corporate/news/2017041701.html

It won't be made available until 2019.

There is an alternative currently available, the BriTek tire: http://www.energyreturnwheel.com/Home.aspx

Has anyone seen or ridden on one?

 

[Adam riding downhill]

Obvious questions:
unsprung weight
durability
repairability
service (bearings, truing)
compatibility
It looks heavy. Wheels have to be light and strong. Wheels (on bikes) tend to need to be trued and don't stay round. How about electric bike applications?

 

[Nutella]

Add to the obvious questions:
How does it ride in a cross wind? Even high profile rims turn into sails and make a windy ride fairly terrifying.

I hope it's a very expressive gadget....

 

[Alex M]

Recycled resin is nice, but the item is disposable. Looks like only bushings/bearings could be replaced.

So... even with a disposable culture of North America the big question is price per mile of run.

Also, the comfort/performance won't always be the same as with air fill. Air-filled tubes absorb shocks coming from any direction, while this invention seems to favor vertical loads more.

Puncture-proof, I like this. But then, if the trail is particularly thorny, an air-filled tire can be used with a thicker wall tube, or Slime, or liner (and replacing it on the road isn't that terrible).

 

[Nicolas]

Yes, good points. Pros, no need for air and should last a damn long time. Cons, I don't like the idea of a disposable anything.

Ideally, it should have exchangeable tire surfaces. We could strip one for road use and another for off road.

In terms of lightness, which should answer the unsprung weight problem, this would be ideal since we have a wide option of material, material thickness and density, available. The spacing of the blades would handle the tension and the desired amount of shock absorption.

I'm really not sure I understand what is holding back this technology, short of outdated business models. The technology is here.

 

[Nirmala]

Tannus has been selling airless tires for a while now, and they work on normal bike wheels: http://www.tannus.com/

 

[Jeff Backes]

Also, do a google search for tweel, They tried this on the Segway and the different weights of riders made it impossible to get a good ride for all body types.

jeff

 

[Nicolas]

I guess there needs to do a lot of lab work figuring out the right amount of blades, their composition, spacing, etc. It just seems like such a given to me.

I used to have a few contacts at Michelin. I'll try to contact them next time I'm in France. I'm sure they'll have looked into it by now.

 

[Jeff Backes]

Michelin was the original inventor of the tweel. It finally did come to market but only for heavy equipment.

jeff

 

[Nicolas]

Michelin was the original inventor of the tweel. It finally did come to market but only for heavy equipment.

jeff

Nice, I thought they would have made a bicycle version of it.

 

[Nicolas]

A couple of points about the Bridgestone wheel:

- If you have a mountain bike, you might want to run high PSIs for your daily commute on paved roads, but take some air out when you head out onto technical trails. And you're telling us that we have to change the entire rubber tire to do that? You've got to be kidding... All that's needed today is a small pump!

Nope, just a strip that would snap around or tie around. I'm not an engineer. T was just a thought.

 

[Alex M]

Tannus is a different creature from this Bridgestone "blades".

The former is an airless tire, you can put it on a regular bike rim.

The latter is a complete wheel set, with "tire" integrated into the wheel - blades together with the outer rubber strip work as a tire. I am skeptical about replacing the outer strip at will - it should be attached as permanently as possible, or it would detach when the wheel deforms under way. This is exactly why airless "tubes" are not popular on adult bikes - you know, a $10 rubber noodle that you put on the rim under the tire.

Tannus have apparently come with a work-able solution for their airless tube/tire combo, with plastic pins holding everything together. Though at $70 per Tannus combo I would rather carry a spare tube.

 

[Nutella]

Variable psi is a good point. Finding the sweet spot for any specific tire for me can be just a few psi on a mtb tire and +/- 5 or so for me on the road. I'm kind of a nerd that way.

 

[emco5]

It resembles the resistance fan on an exercise bike.

Drag: the sum of all the aerodynamic or hydrodynamic forces in the direction of the external fluid flow. It therefore acts to oppose the motion of the object.