Only 20,000 will have their places confirmed to ride, drawn by ballot when the entry window closes on either 4 January or when 75,000 have registered.
The £48 ride on a closed circuit based on the Olympic road race route will form part of the RideLondon cycling festival which will be held annually in the capital from August 2013.
Hugh Brasher from organisers the London & Surrey Cycling Partnership, said: “We expected a high demand, but even we were surprised by such a fantastic reaction to the opening of the entry ballot, and we feel this is a great start to one of our primary goals to make this the world’s largest charity fundraising cycle event.
"Furthermore, the current figures show that over half the registrants have never previously ridden in a cycling sportive, so we are especially pleased that this event seems to have struck a chord with new participants to this type of challenge."
Forming a key part of the Olympic legacy, the RideLondon weekend will include three other events:
- RideLondon Freecycle: A 70,000 all age and ability ride through the closed road streets of central London
- RideLondon Grand Prix: An invitational city centre criterium race with a focus on women’s elite, hand-cyclists and age group cyclists. It will attempt to showcase Olympic cyclists of the future and see racing around a 1.3-mile loop close to The Mall
- RideLondon Classic: Set to attract many of the world’s top pros and is expected to become part of the UCI’s race calendar when it’s announced in September. It will be broadcast live on the BBC and will follow a variation of the Olympic road race route, following the same course as the RideLondon 100 with a route extension to meet UCI pro race requirements
For more information potential participants should visit the RideLondon website.