I had a big revelation this morning. One of the niggling concerns I'd had about the Christiania involved my left knee, which has given me various troubles since the mid-90s. My knee hurt quite a bit going up stairs last night, and it was almost certainly because of my use of the trike. Since I would start from a standstill by pushing on my left pedal, there was a lot of pressure, and that didn't do me any good.
But it also seemed that the saddle was a bit low, so last night I raised it by four inches or so.
And today it was a whole new story! It seems to pedal easier, and I'm much more comfortable all round. No more knee pain on the bike, and much less off.
Result! Though I guess one could argue that I should have known to do this before leaving the shop with it...
In any case, I took Gem to nursery in it this morning and it was a great ride. We both really enjoyed it. I took a roundabout route home and tested it on some minor hills, and no problems at all!