Terra Tiger Tires: Fill them with foam??

Terry,

I asked a tire dealer about it for lawn mower tires. They do it there so its not them trying to keep from sending my busness somewhere else. unless you tires are very new they won't fill them. they also said putting foam in low pressure tires is very unsatisfactory. the tires will not flex like they should. If you lok at the links you posted it states the lowest weight foam is simlare to 25 PSI. If you went and put 25 PSI in your current tires you will have very hard rocks If they'll stay toghther. We have it in our Manlifts at work. its great we never have a flat no mater how mant nails are stuck in the tire. But it will get stuck in 1" on snow. or even on a wet floor. the tires have no flex at all.

would spray expandabel foam inaulation work? i have thought about trying it. we need to eaither convert our terra tiger wheels or hope someone comes up with a way to fix the originals.

There's more than one flavor of tire foam... heavy foam is excellent ballast, and very tough.  Light foam is as tough, but has enough air content, and different composition, so it rides nicer.  I have heavy foam in some of my garden tractor tires, and in my zero-turn commercial mower's drive and caster tires... and have used it in heavy equipment... I also have light foam in other tires... four on my dad's boat-dock, and in some of my hand-carts and garden carts.

Obviously, if you're looking for ballast, the heavy foam is what you want.  If you're just looking for puncture-protection, and don't want it to be too heavy, light foam is the answer.

Heavy foam WILL make it ride very firm... light foam will not be as hard on your back, and that's simply because the light foam is less dense.

When they shot foam into my tires, the tire shop indicated that they could vary the 'feel' of the tire a little, by increasing or reducing the injection pressure of the tire.  Regardless of how it's done, They DO ride smoother than tires fully filled with fluid, because both foams are compressible to some extent-  fluids are not.

The major disadvantage to tire foam, is that it has the same, albeit greater inertial impact on the vehicle, than you'd experience with tires full of fluid.  When you accellerate a heavy tire, there's an inertial resistance... like a big flywheel being brought up to speed.  When it comes time to stop, you have to not only stop the rolling load of the machine, trailer, and tires, but also the weight of the foam or fluid... but with tire foam, you also have the rotational inertia.

You don't have the same situation with fluid-filled tires, because when you start rolling, the fluid can 'flow' inside the tire, rather than spin.  Once moving fast, the fluid in the tire MAY start spinning... but when you stop the tire rapidly, the fluid can keep spinning around, hence the inertia you'll deal with is much less... like having a big iron weight, but spinning on wheel bearings instead of rigidly fixed to the rim.

One of the reasons why tire shops don't like to shoot foam inside an old tire, is that it's possible for the tire carcass to rupture doing the foam injection process... which not only wastes a large investment in foam, it leaves you without a tire, and the shop with a huge mess of heavy, hardened jelly all over their shop.

One thing I'm waiting to see more of... is 'airless' agricultural tires, like what's used on skid-steer loaders... they're out there... but since the contact pressure is higher (and less pliable) the tractive effort given will most likely be less than a pneumatic tire... more like what's found in a cleated steel wheel.