We are gradually changing our wheels over to being fitted with tubeless tyres. 

In simple terms it's a wheel fitted with a proper canvas re-inforced rubber tyre (similar to the ones fitted to your car) but, instead of having an inflatable inner tube, it has a high-density foam insert: 

So why are we doing this?  Because it gives you all of the advantages of a pnuematic tyre wheel with none of the hassles of keeping it blown up or dealing with punctures. 

But don't confuse these wheels with the wheels on a lot of buggies.  They are often foam wheels without proper tyres that, if fitted to a go-kart, would wear out very quickly and wouldn't run very well.

They also give you an improved ride as the tyre cushions the bumps.