I've just sent Abs my (partial) route -
but it is not posted anywhere online so can't share (without a bit of fiddling)
Edit - here it is. The relevant bit is on the right of the route - Hertford to Shepreth area.
http://www.bikely.co...-Counties-Audax
I like the first bit of Luke's route, which seems to start off like the Dunwich Dynamo
I also like Abs idea of going over Hampstead Heath / Spaniards and out that way.
But not keen on the A10, either for getting out of London, or getting in to Cambridge.
I would follow Luke's route but then where it dog-legs left at Furneaux Pelham, cut through the lanes via Langley, Duxdford, Gt Shelford and Grantchester - which is a nicer way into Cambridge.
I guess we need two routes - one out and one back!