Avebury/Wiltshire Downs

anyone cycled to/through that part of the country? a mate of mine and i want to avebury/silbury hill in a few weeks, and i'm struggling to find any info about camp sites in the area between london and there. ideally i think we'd like to ride for 65-75 miles and then camp, hang out for the evening, then ride the rest of the way and camp in/around avebury as well.
so, anyone else done this route before? know of a good route that would avoid any highways, and/or know of any campsites in between here and avebury, and then at/around avebury?
thanks for any input!

If you've got reasonably fat tyres...cycle along the kennet and avon canal and stop here:

http://thegoldenswan.co.uk/

nice pub with camping in the back.....there's another pub with a similar setup only a couple of miles further west along the canal and right alongside the canal too...can't remember it's name....I have only camped at the Golden Swan though.

found the other one:

http://the-barge-inn.com/

we got the train from Reading and rode along the canal in one day to The Golden Swan, you could possibly even ride along the Thames path to Reading then switch to the canal towpath, but does need fatter tyres though.

fatter tyres as in 26x1.95? or would 700 x 28/32 do the trick. probably not, eh? does lok quite nice though.
thanks!

my girlfriend rode it on an old raleigh hybrid with 700 x 35's semi knobblys, I had a conti cross countrys, she only had to walk in a couple of short sections.....but wouldn't really recommend it with road tyres.....

i'll be using schwalbe marathon pluses:

maybe?

maybe....out of Reading was pretty smooth, but it's pretty variable, from gravel, to mown grass, to unmown grass, to hard mud to fallen banks.....but it's miles and miles without cars or traffic lights, or many people for that matter.

Csn't help but I a know the area and am jelouse, it will be a lovely ride. Winstons Route sound ace.

How far to the camp site from Reading Winston? Could be a good ride for the girlfriend and I.