Well I enjoyed the 100km. Wetter than expected for the first half (I thought of asking for my money back, given the promises of fair weather
), but a really pleasant circuit.
It was very much a ride of two halves for me. It wasn't too far from home, so the area is familiar, but the roads were new once we got out of Cambridge, until Steeple Bumpstead, after which I knew them all.
I played tag with the tandems most of the way round - they were faster than me, but kept stopping to admire the views
Eventually, though, they came past yet again, and then dropped me on the run in.