Folding Bikes - Air Free Tyres - Could they be OK?

Do you think there will ever be good solid tyres? The inconvenience of a flat is huge for a commuter, or any cyclist really. I'd have thought that some enterprising materials scientist could come up with a solid bike tyre system that would be resilient, low rolling resistance and still have a degree of 'give' in it.

There are people marketing such tyres including a manufacturer not too far from where I live.

What do you think?

An American seller (edit - see warning in post #4)
http://www.airfreetires.com/shopping...aspx?pagenum=2


A UK manufacturer
http://www.greentyre.co.uk/tyres.html

You read about peopel trying them out ewery now and then. Can not remember reading about anybody tryed them out for folders. I guess they need to be made better than the present ones for peopel to choose them? If you`we got more than one bike you could have one with such tyres.

Tonight I am going somewhere around 20.00 hrs (pich dark), only 2 km ride, -3C. I am not in the mood for fixing flats in the dark and comfort is not a big problem on such a short ride. Also I think if I knew I was riding to the train or bus early tomorrow morning, no time for flats I would maybe also choose such tyres.

Personally I think it's a big investment to commit to one tire pressure at the time of purchase. So if you're depending on the tire for suspension, pneumatics offer a better value because they are adjustable.

However, I think polyurethane would be great if you had a high quality adjustable suspension like a Moulton. With lower rolling resistance and less maintenance what's not to like?

Bottom line? Don't buy from airefreetires... they took my money, I never got my tires, and I reported it too the CC too late (because of AFt's assurances that 'my tires were due in any day') for the CC company to do anything about it.

Buy direct from teh manufacture if you want to try them out NuTeck (http://www.nu-teck.com/news.html)

People have been trying to invent good air free tires since the pneumatic tire was invented - with zero success - except for certain limited uses - like vehicles that move on rails or slow moving heavy equipment. The thing is air distributes the impact pressure of the ground all throughout teh tire, whereas a solid tire sends the impact straight up.

How about tank treads, like this?

http://www.popsci.com/crescent-shape/article/2006-08/your-very-own-personal-tank

:)

I agree with what you people are saying about the problems of flats. I'd certainly think about buying some for my Strida knock off. The tyres it is fitted with are kind of low pressure, though I'm riding them a lot harder than the sidewall says. I had a puncture from a piece of glass a couple of weeks back and I'd only done about sixty miles on the bike from new. I was thinking of looking into some marathons, but they're not sure to resist glass. I emailed the UK tyre maker linked to above and when I find an outlet, I'll see what they cost. Maybe the factory will sell direct. I also need to measure the bead width of the rim. These tyres are very fussy about that since you can't just blow them out to fit.

The manufacturers are claiming that the tyres are as light or lighter than regular ones, and ride well. I've seen comments that they are squishy, but you never know what make of tyre these comments refer to. These polyurethane mixes can be made to have different pressure characteristics too. I'd love to hear from someone who'd ridden the new types that are on sale.

Bottom line? Don't buy from airefreetires... they took my money, I never got my tires, and I reported it too the CC too late (because of AFt's assurances that 'my tires were due in any day') for the CC company to do anything about it.

Buy direct from teh manufacture if you want to try them out NuTeck (http://www.nu-teck.com/news.html)

That's a bummer. Thanks for that link to the manufacturer. I edited my original post to reflect your inf about them being a reseller.

These polyurethane mixes can be made to have different pressure characteristics too.

Yeah, but as werewolf said those pressure characteristics are directional whereas air pressure is isotropic.

However, since they can be made harder than pneumatics they do seem to dovetail nicely with the Moulton design philosophy: Optimize the wheels for a glass smooth surface and design a dedicated suspension to translate that performance onto rougher surfaces.

Why compromise on ride quality and performance with the soft ones when you can get a win win situation by using the hardest ones available on a bike with dedicated suspension?

I saw a prototype of an air-less tire years ago... it makes good sense to me.

However, I do have one concern. If you can stretch an airless tire into a rim, what's stopping it from coming off (you can't take off a conventional tire once it's inflated). Obviously, these things have been tested extensively otherwise they wouldn't be released into the market by now... so I have to assume it's not an issue.

I hate flats, so I'll be keeping an eye out for user feedback on this thread... :)

Yeah, but as werewolf said those pressure characteristics are directional whereas air pressure is isotropic.

However, since they can be made harder than pneumatics they do seem to dovetail nicely with the Moulton design philosophy: Optimize the wheels for a glass smooth surface and design a dedicated suspension to translate that performance onto rougher surfaces.

Why compromise on ride quality and performance with the soft ones when you can get a win win situation by using the hardest ones available on a bike with dedicated suspension?

Interesting point.

I'd also be concerned, intuitively, that non-pneumatic tires would be hard on the spokes, and might not grip the road as well, especially when cornering at relatively high speed. (BWDIK)

Try tires with thicker tread and use thorn resistant tubes. I just ordered some today for my R20.

I suppose airless tires could be a good idea for folders though, if used along with folding wheels...
http://www.youtube.com/watch?v=nlRt3YOl00c
http://www.duncfitz.co.uk/wheel.html

Yeah, but as werewolf said those pressure characteristics are directional whereas air pressure is isotropic.

However, since they can be made harder than pneumatics they do seem to dovetail nicely with the Moulton design philosophy: Optimize the wheels for a glass smooth surface and design a dedicated suspension to translate that performance onto rougher surfaces.

Why compromise on ride quality and performance with the soft ones when you can get a win win situation by using the hardest ones available on a bike with dedicated suspension?

Yes - that's the compromise of all our small wheeled non-suspension bikes, and Moulton sort of solved it. The manufacturers of these say they can make them in any kind of pressure profile from 10 psi to well over 100psi. I think it's all a matter of how much gas they have inside the mix when they spin the polyurethane fluid into the moulds.

I'm not sure exactly what effect the directional Vs isotropic reaction would have on the rolling tyre. I think we should bear in mind that when the makers say they simulate various psi, they mean it rides 'like' whatever psi they say. I'm guessing a bit there though.


Interesting point.

I'd also be concerned, intuitively, that non-pneumatic tires would be hard on the spokes, and might not grip the road as well, especially when cornering at relatively high speed. (BWDIK)

Why do you think they would be hard on the spokes? I'm sort of supposing that an airless tyre rated at 55psi rides somewhat like a 55psi pneumatic with similar reaction to road imperfections and load.

I'd quite like to try one on the back of my Strida Knock off if they are under about £20. I really hate having to dismount and walk with a flat tyre.

The Nu-teck FAQ (http://www.nu-teck.com/history1.html#where) answers parts of these questions. They say they've tested them thoroughly but don't describe but what device their tires manage to stay on the rim in the absence of air inflation. Nothing addresses spokes that I see.

Why do you think they would be hard on the spokes?

Because on a couple occasions I have broken a spoke or two by hitting a bad bump with my tires pumped up really hard. I figure the sharp impact sends a shockwave up the spoke, and when it reaches the flange it rips the head off the spoke. I really don't know whether there's any validity to this, though.

I saw a prototype of an air-less tire years ago... it makes good sense to me.

However, I do have one concern. If you can stretch an airless tire into a rim, what's stopping it from coming off (you can't take off a conventional tire once it's inflated). Obviously, these things have been tested extensively otherwise they wouldn't be released into the market by now... so I have to assume it's not an issue.

I hate flats, so I'll be keeping an eye out for user feedback on this thread... :)

As I understand it, you need to use some special stretching tool to fit the tyres. It's supposed to be quick to fit them, but I think they stay on once fitted. Some of the FAQs mentioned in a post just above this cover their ability to stay on the rim.

Can not belive it is harder on the spokes than a 100psi pneumatic 20 x 1,3 tyre?

I've considered these as well. The rear wheel on my Qile Duo VSTII folder is a b***** to remove, because there are so many things to loosen (kickstand, rack stays, fender stays, rear band brake cable, etc.). AirFreeTires is actually located right here in my city (Orlando).

While I don't have personal experience with them, years ago, I used to participate in a recumbent bicycle forum. There was a member of that forum who owned a high performance recumbent (Goldrush Replica), and he bought a set for his bike. He liked them very much! In fact, he started a thread on the AirFree tires that stayed in the first page of the forum for several weeks, resurfacing every now and then whenever some one had some comments.

But this bike owner reported that the tires rolled just as efficiently as the high pressure pneumatic tires he had replaced, and was most gleeful that any worries about having flats were now far behind him.

So I guess YMMV applies here.

Regards,
Edward




Do you think there will ever be good solid tyres? The inconvenience of a flat is huge for a commuter, or any cyclist really. I'd have thought that some enterprising materials scientist could come up with a solid bike tyre system that would be resilient, low rolling resistance and still have a degree of 'give' in it.

There are people marketing such tyres including a manufacturer not too far from where I live.

What do you think?

An American seller (edit - see warning in post #4)
http://www.airfreetires.com/shopping...aspx?pagenum=2


A UK manufacturer
http://www.greentyre.co.uk/tyres.html

That's a bummer. Thanks for that link to the manufacturer. I edited my original post to reflect your inf about them being a reseller.

Regardless of my bad experience with the reseller. I still plan on trying some NuTecks on a "beater bike" (SS or Fixed Gear that will be pretty much guaranteed to get me to work) at some point. I have ~ 5 mile commute so as long as their no too rough, the potential reduced efficiencies will (I suspect) pay for themselves in reliability. Actually, I've considered making my own "spiker" tires out of some... but those are projects for later...

Somewhere I saw a discussion of airfree tyres, and the conclusion was that a particular brand was not bad at all. They have come a long way.

Somewhere I saw a discussion of airfree tyres, and the conclusion was that a particular brand was not bad at all. They have come a long way.

For sure on the Dahon forum a few years back.. "pumpkinhead" wrote some on the airfree and liked them a lot.. here's one THREAD (http://www.dahon.com/forum/index.php?showtopic=2726&st=0&p=18358&hl=airfree%20tires&#entry18358)

Yes, absolutely there have been useful air-free tires for generations. You just need the right application. I have pedalled air-free tires on two continents. Cast aluminum in Ouray, Colorado and cast iron in South Africa. Four-wheeled bikes used in underground mines. Miners and mechanics used them to get around so they would not have to tie up an engine. In Colorado we used light aluminum wheels as we had to be able to lift the bike off of the tracks by our selves to get out of the way of ore trains. In SA I always had a work team with me and they lifted the 6 man iron wheeled bike off of the rails for me.

For sure on the Dahon forum a few years back.. "pumpkinhead" wrote some on the airfree and liked them a lot.. here's one THREAD (http://www.dahon.com/forum/index.php?showtopic=2726&st=0&p=18358&hl=airfree%20tires&#entry18358)

Useful to read someone's direct experience. Thanks for that.

I just phoned the UK manufacturer GreenTyre and they sell direct to the public, so I am going to measure my internal rim size on the strida knock off and if it is between 22-25mm, I will be sending for some of their 47-305 tyres. They are £13.99 which is cheaper than a Marathon here, but they do make a £10.99 consignment charge which bumps up the price a bunch. On the other hand they are only 32 miles away from here so I might just drive there if they will deal over the counter.

Since I started this thread, I suppose it is beholden on me to test them and report back. This all depends on my rims having suitable internal dimensions.....

^ So, are you still going to give them a go? :)

^ So, are you still going to give them a go? :)

I think we crossed posts there Poko, I was editing mine and saying I was going to buy some when you posted that. As long as they will fit my internal rim size. That is a crucial element with these, because unlike pneumatics of course, they can't adapt to a smaller or larger rim size and it's the internal rim that holds them on. The web site gives the required internal measurement.

If you look at the diagram above the rim size figure, you can see why it is important for a solid tyre.

http://www.greentyre.co.uk/tornado.html

I was at one time, a Measurer of Road Running Courses, and for this used a bike with a solid front tyre.
A mechanical counter reads the distance travelled by the calibrated front wheel and it is vital that the circumference of the wheel remains constant throughout both calibration and measurement. A loss of pressure would invalidate the result.
The choice of tyres was limited, the ride fairly harsh, and I always went back to a pneumatic tyred wheel for normal cycling.

I think we crossed posts there Poko, I was editing mine and saying I was going to buy some when you posted that. As long as they will fit my internal rim size. That is a crucial element with these, because unlike pneumatics of course, they can't adapt to a smaller or larger rim size and it's the internal rim that holds them on. The web site gives the required internal measurement.

If you look at the diagram above the rim size figure, you can see why it is important for a solid tyre.

http://www.greentyre.co.uk/tornado.html
Tyre sizing information about genuine Stridas:
http://www.stridaforum.com/forum/viewtopic.php?f=4&t=2416

I have some on one of my other 700C bikes from airfreetires. The one I have is supposedly equivalent to 700C x 20 @ 150psi and I can tell you it feels like it. Very hard. But I have no problems with it for over a year now. Hope this helps.

I used airless tubes in my tires years ago (No More Flats brand) they are HEAVY! On my mountain bike, they seemed to have doubled the weight of the bike. Flats suck, have you given thought to tire liners and SLIME to prevent flats? The liners and SLIME do not add anywhere near the weight of the airless tubes and I would think, airless tires, which would be about the same thing, also, when the tires wear out, it is a LOT easier to replace a pneumatic tire than a "solid" one.

I used airless tubes in my tires years ago (No More Flats brand) they are HEAVY! On my mountain bike, they seemed to have doubled the weight of the bike. Flats suck, have you given thought to tire liners and SLIME to prevent flats? The liners and SLIME do not add anywhere near the weight of the airless tubes and I would think, airless tires, which would be about the same thing, also, when the tires wear out, it is a LOT easier to replace a pneumatic tire than a "solid" one.

The thing is, these urethane tyres are supposed to be lighter than ordinary tyres. They are a solid moulding with built in bubbles that simulate particular pressures in ordinary tyres. You can even order specific characteristics if you want them.

I was very interested in the accounts of people who have used these kinds of tyres. Good or bad - the only way to tell is for people to use the ones that are now available and report on them. That's what I'll do if I can get a size to fit my rims on the Strida knock off.

Thanks to Amuro Lee for the link to info about genuine Strida. That's the size I think mine is, but I need to measure the rim internal width. The 47x305 Tornado tyre sold at £13.99 by www.greentyre.co.uk should fit as long as my rim internal width is between 23-25mm. I'll measure it when I get the chance to whip off the original tyre. The manufacturer is located only 32 miles from my house. I can jump in the car and drive down there to avoid their rather high consignment charge. I can also take my original tyre with me just to make sure I am buying something that will work on the rim.

EDIT:

THE 305X47 SHWALBE MARATHON WEIGHS 460GRMS
THE 305X47 SOLID FROM GREENTYRES WEIGHS 420GRMS AND HAS NO TUBE.

The thing is, these urethane tyres are supposed to be lighter than ordinary tyres. They are a solid moulding with built in bubbles that simulate particular pressures in ordinary tyres. You can even order specific characteristics if you want them.



Evil1, have you checked out the knockoff AirFree tires yet? money to be saved I hear... but more importantly to me, what color do you fancy?

The manufacturer is located only 32 miles from my house. I can jump in the car and drive down there to avoid their rather high consignment charge. I can also take my original tyre with me just to make sure I am buying something that will work on the rim...

Just sitting here... waiting... waiting for your product report... :D

.

hmm, airfree tyres would not work for me, since i have to deflate my tyres to reduce the wheel size so that they fit in the suitcase for air travel, as this is the reason i have a folding bike.
otherwise, i might have given them a try.

Evil1, have you checked out the knockoff AirFree tires yet? money to be saved I hear... but more importantly to me, what color do you fancy?

What? You can get KNOCK OFFS??? Where? Show me NOW! I want them.

:)

^ Maybe you can get purple or dark blue tires to match you strida knock-off??? :eek:

That'll be really pimp!!! :) :thumb:

^ Maybe you can get purple or dark blue tires to match you strida knock-off??? :eek:

That'll be really pimp!!! :) :thumb:

I get enough stares as it is thanks very much. I don't want to get a name as, 'that wierdo that rides the pimped up freak bike.'

The greentyre co do produce these things in a rainbow of colours though.

I tried Amerityres (or however it's spelled) on my Speed P8.

They were squirrelly, and reduced my speed by 1 or 2 gears.
So I put them on a cargo trailer and installed Schwalbe Marathons.

Honestly, I'd say skip it.

CE

Schwalbe Marathon Plus... problem solved.

Schwalbe Marathon Plus... problem solved.

That's true... l like mine .. yet to flat in over two years and tons of goats head thornies .. but OP Evil5 wants something for ERTO 305mm tires...

Bummer - the dimension of my inner rims is wrong for the locally produced airless tyres. They require a rim width inside of 23-25mm. The dimension of my knockoff strida rim inside is 21mm. The company say that this is not suitable, so I will not be able to trial them after all. That's a shame because they were very helpful people and offered to fit them free if I brought the wheels in with me.

http://greentyre.co.uk/

^ :(