Hi Henning, Werner et al,As I suspect you unerstand German quite well, these two articles from the Fahrradzukunft might be interesting for you:
Many thanks for the interesting links and comments. I go along with pbjosh that a single speed is more fun and a fixie goes a step further.
However, as my recent performance level is closer to 50 W, I'm more inclined to believe the results of the second test .
Perhaps I'm getting too old for this anyway after a really stupid and almost stationary accident, when I fell off my Pedersen.
The diagnosis after a CT yesterday showed a crushed 1st lumber vertebra so it looks like an enforced six week pause for cycling and birding!