I did the 'cross again tonight. Sprinted with the randoms at the back of the vets grid and hung on for half a lap. Then realised I didn't have my GPS turned on, and finally, on a tight off camber right hander towards the end of the lap I crashed! While I sorted myself out (and attached the course tape which a previous person had trashed) all the juniors went past!
I grazed my knee and elbow and jarred my shoulder a bit, but no real damage done, so I ended up time trialling around for a while. Then I heard a bell, so I tried to go fast and catch the person in front of me. I caught them, but it turned out the bell was actually for the juniors, so I had to do another lap at that pace! That really hurt, but showed that the TTing bit wasn't as fast as I could go, so next time I shall have to try to do that for the full 50 minutes!
I want to get a cross bike. They are soo much faster on the dry and concretey bits!