Marathon 2011 -alert-alert-alert-

Hope this info is useful...

It's not unprecedented for bike rides to proceed ahead of a popular* City Marathon

http://www.wolverhamptoncitymarathon.co.uk/marathon-history/

Cycle event - appeals particularly to families. The cycle event has grown beyond expectations and is now one of the most popular events.
Maybe LFGSS could work with the London organisers to look at the model used in W'hampton, with a view to replicating this in the future in London. Get Boris involved** or something.

*the race not the city

** only kidding