What do I do, clever people? I seem to remember a valve thing coming with the original package which of course I've gone and lost. And do I pump it up with a bicycle pump (which of course I don't have) or take it to the garage and use their air machine and overfill it and explode the thing?
And what happens if it's a puncture? Have visions of messing about with a bicycle repair kit which is beyond my capabilities.