This illo from Triathlete's World (captioned "Will My Commuting Bike Embarass Me?") made me think of the Brommie Worlds:
I'm very tempted to go, you know. It'd be a perfect decompression event after my half-ironman the week before!
Here's the entry page and
rules. Registration is open until a couple of weeks before the race. Two 6.5km laps, in suit and tie. I may need to borrow a bigger chainring..!