I biked back along the Thames, doing the 26 or so miles back to Richmond in about 3.5 hours with a 1/2 hour for lunch.
This was slower than I expected but it took time to figure out where I was going (since I wasn't familiar with the route as opposed to last year along the Charles). There were some stretches I made good time (Staines to Shepperton, Hampton Court to Kingston, both of which probably averaged 20 MPH), but there were also some dead ends and some badly marked paths that caused me to go out of the way. Also bicycling on sand / gravel is a lot slower than asphalt. While most of the MDC / Charles River Paths are paved, most of today's were not. While I like "mountain bikes" for their stability, the extra surface area on the tires probably adds to drag. This was only the second time I'd ridden a mountain bike for any distance. Unfortunately what I really want is a mountain bike frame / tires geared like a road bike. (I rarely used anything except for 14 and 21 on the bike today; it was 21 speed - 3 x 7; I used 7 on occasion going up some steep short hills.)
I was really hoping to make it as far as Waterloo or at least Clapham junction, but after Richmond, the path got even more confusing. I stayed along the Thames, perhaps as far as Putney, but eventually started heading back and wound up picking up NationalRail at Barnes (as opposed to Waterloo / Clapham Junction).
I suspect I biked about 40 miles all together in about 5-6 hours.
I took the bike on the train back to Windsor and returned it. It was interesting to note that all the touristas had taken Windsor over by 5 PM. When I got there at 10 AM in the morning it was fairly quite.
Oh, and the drunk foreigners behind me in the lounge (see previous post) as starting to loudly recite bad poetry.
I should either go to bed or go get another drink.