Trial ride complete. It's about 15k or 9 miles thirteen chains, or fifteen half horses and twenty one dessert spoons or whatever the imperial fractions are. The ride in took 35 minutes and the return took 45 minutes, because there was a headwind and I investigated a longer but more scenic route back.
From experience this year the wind blows north in the morning and south in the afternoon, so I should be travelling with the wind in both directions.
Photos didn't happen as I was timing myself but I'll be riding the route again soon: my legs are telling me they need the practice...