I haven't read all the recent replies, however my Sister in law, who used to be with the Beeb says's this.....
Yes all proposals for BBC TV and online content ideas must be submitted online through e-Commissioning ...check out http://www.bbc.co.uk/commissioning/tv/pitching-ideas/e-commissioning.shtml. He would probably have to mock up a programme 'treatment' (a detailed propsal with a 30 min episode idea) but all the info should be on that link.
The direct people concerned with that programme idea would probably be someone like Alison Kirkham (Commissioning Editor for Factual formats and features) or Abigal Appleton (Commissioner for BBC Learning).
I reckon it's a good idea as there aren't any really bikey programmes on the Beeb at the moment - but it would need a bit of an edgy quality to it (think Top Gear for bikes!)