Out of the department, out along Trumpington Road, left onto Long Road, right onto Hills Road. Past Addenbrookes, Hills Road turns into Babraham Road, then right (with a big lorry very kindly while I made the turn) onto Granham's Road. Over the hill and back down the otherside for a rest at the level crossing in Great Shelford. Look at the shiny new bike path but it's not going where I want to go.
Right onto Cambridge Road, which turns into Shelford Road, and takes you back towards town. Right onto Trumpington Road and immediately left into Maris Lane then left onto Grantchester Road and wind through the pretty lane into Grantchester itself. Take a sharp right at the High Street onto the bike path down the back of the Green Man and then across the meadows to come out in Newnham. Stop at the co-op to buy greek salad, more tomatoes, a banana, a yoghurt and some water. Finish off along Newnham Road and Fen Causeway, and re-enter the dept from the other side.
About 9.5 miles and took just over an hour, so a very slow average speed. But you can't go fast along the meadows or you'd shake to bits and run people over. And the hill on Granham's Road was a headwind.