are they any good? i seen someat the store i work at. i thaught of getting some for my bike.

Are these the "thorn proof" type (which are just thicker rubber); the Slime filled ones (that may seal themselves on small punctures); or the solid, no-air-required-but-they-weigh-a-ton-and-ride-terrible type?

I wound up with one by accident. Mine just has thicker rubber on the bottom. It certainly does slow me down but no have not had a flat on it. My commute is short so I take that bike when I can use a bit more exercise.

There is no such thing as a flat-proof tube. There are some that are flat-resistant, usually by making the tube from thicker rubber, and there are some that claim to be able to self-repair small leaks, but I've had flats with both.

If you want the most flat protection you can get, start with a kevlar-lined tire like an Armadillo or a Marathon Plus, add in a tire liner, and then put in the thick tubes. It'll weigh a ton, but it will be pretty flat-resistant.

Personally, I use kevlar-lined tires with tire liners, but just regular tubes. I haven't had a flat since I switched to this configuration and I pass through an industrial area twice a day.

I saw some of those thick foam inner tubes - like 'swimming noodle' foam, at a store today. You put them in instead of an inner tube.

I think that might be good, but I can't figure out how you would get the tire on. Does anybody know if these are any good (specifically for mountain biking?)

I am riding a rough 29-mile trail this weekend that has huge 1-inch thorns in places, and I usually get multiple flat tires there. If I can stick some of those foam tubes in there, I might do better.

Only thing flat proof is solid rubber tire. I had a slime tube and a thorn resistant tube puncture within the same day. Strangely both punctures happened when the bicycle was parked.