Russ has posted in the forum (you need to log in), seeking interest in riding the Chiltern Hundred in 2013. He's identified four riders so far, but I think he's after eight for a team. The event offers three distances:

button the Gran Fondo of 177km (110 miles), with ascent of 2,620m.
button the Medio Fondo of 120km (75 miles) climbing 1,760m.
button the Corto Fondo an 92km (58 mile) challenge ride with hills and great views for all-comers.

The date is June 3rd, by which time I'd hope there would be some decent weather! If you're interested, leave a message in the forum, or contact Russ directly.