I once bet on the 2006 World Cup and won £90 from a £2 or maybe £1.50 bet. It was quite a slim chance of getting it right. I bet 0-0 by full time with Zidane to score in extra time for France.

Betting is tiresome and pointless, you'll always loose in the end, with Bradley Wiggins odd on favourite for yellow it would be no use betting on him to win, it as you'd get pennies back the odds are so strong in his favour and betting against him wouldn't be fair or supportive.
So I'm going to take Ben's Mums daily predictions and bet £1 and guess the winner of the stage.

Sky Bet are currently offering a free £10 when you open your account and put £10 into it.
That's £20 to bet with and there are 23 Tour stages.

I'll take it as each stages comes.
1-2 hours ahead of the race starting each day.

Stage 2 - Vise - Tournai, flat stage
Ben's Mum said Cav to win

I wasn't so sure as he only has Bernie Eisel as a leadout and I thought the bigger wider sprinters with full leadout trains would fair better.
Cav odds were even - stake £1, get £1 back.

So, after everything I said I bet against Ben's mum and went with Andrei Greipel who had odds of 5/1 (still a big favourite)

£1 stake gets me a £6 return, £5 profit


Updated result:
Greipel pipped to the line by Cavendish. Ben's Mum picked the winner, I picked 2nd. 
£1 to Sky. Damn.