Audax rides

http://www.willesdencyclingclub.co.uk/about/audax/jack_eason_rides/
http://ridewithgps.com/routes/3758356

The 200k looks interesting to me, though it'll end up being closer to 300 by the time I ride out and back:

"200km cycling event starting from Maidenhead. Controls at Shere, Dabbling Duck, Petworth, Hungry Guest and Alton, Cafes Shops Pub, plus 5 information controls.
A new ride for 2014, in memory of Willesden CC's Jack Eason, randonneur of the millenium. It takes in the North Downs, Leith Hill, Blackdown, Hindhead, the Hampshire Downs.
Why 'Struggle' - it's because when people asked Jack how he was getting on in a ride he'd often say 'Strugglin''. While the main climbs are some of the longest in the South East and give a challenge, the rest of the route is reasonably flat and rides through some lovely countryside."

Organiser here. There's also a 100K event, 10 Thames Bridges at 0900 same place and date, that I reckon is doable on fixed, even by me, with a couple of short walks on Chiltern Lanes, and a pretty flat 60K ride too. See http://www.willesdencyclingclub.co.u...k_eason_rides/