dependant on what you're driving i would agree mr zarse....
if we go for the thunder karts at Buckmore then any more that 20 mins is gonna kill us all.....
If you go for Club 100, theyre a bit less physical and a bit more "whoooosh" so you can easily manage 40 mins in one.....
if you want the whooosh and the hard work factor, you need to buy ya own kart, gearbox, or even a 100cc is pretty hard going!
Brad - The man who nearly fainted after a run in a thunderkart through lack of oxygen owing to the fact that my suit was too tight!