One of the curses of being a fan of a minority sport (as it is in Britain and the States) is that you feel duty-bound to convince others of its beauty.

So, when the Tour de France starts, we all invite a good friend round to watch a stage in the hope that they'll be won over by the drama, the excitement and the sheer brilliance of the sport - it's probably best to pick an epic mountain stage rather than the team time trial.

Anyway, after about 10 minutes the questions start. Why's he doing that? Who are the blokes in blue? Where's the yellow jersey? What's that bloke doing on a motorbike? Etc, etc. Here are nine of the trickiest we've faced from pals who still think football and golf are better to watch than bike racing.

WHERE DO THEY GO TO THE TOILET?
Answer: The riders have organised wee breaks during a quiet part of the stage and there are strict rules about not peeing where a member of the public may catch a glimpse of Johnson. Avoid the dreaded follow-up question: "What about if they need a number two?"

WHAT'S IN THE FOOD BAGS?
Answer: Cheeseburgers, pork pies, Snickers bars and miniature cans of Coke.

WHY DOESN'T THE STAGE WINNER WEAR THE YELLOW JERSEY?
Answer: There is no answer to this. If people can't work it out for themselves they're best giving cycling a wide berth. It's like trying to explain football's offside law to Americans.

HOW FAST DO THEY GO?
Answer: Very fast. They average 25 miles an hour. The sprints are nearly 40 miles an hour. This impresses even 4x4 drivers who attempt to run cyclists off the roads.

HAS ANYONE EVER DONE A WHEELIE?
Answer: It doesn't happen as often as it should.

HAVE YOU EVER RIDDEN THE TOUR DE FRANCE?
Answer: Depending on your age and waistline you may be able to blag this one.

WHAT DO THE RIDERS DO FOR THE REST OF THE YEAR? IS LANCE ARMSTRONG A POSTMAN?
Answer: Try not to lose your cool. Clearly few people in Britain and America realise that cycling is a full-time professional sport and that the Tour de France isn't just a very long charity ride. I mean, no one asks what Tiger Woods will be doing to make ends meet after The Open. It must be said, though, that trying to explain why Lance doesn't deliver letters in the off-season can be a tricky one.

THEY'RE ALL ON DRUGS, THOUGH, AREN'T THEY?
Answer: Fudge it. Don't say yes, don't say no. Explain that you think cheating is bad and that you prefer to place your faith in the majority of riders playing by the rules. Or fly off the handle and rant: "What, so you don't think there's a problem in (insert name of your friend's favourite sport here)?"

HOW DOES THE TEAM TIME TRIAL WORK?
Answer: No idea. No, honestly, I haven't a clue. Looks good, though, doesn't it!