While the positive effect of the tail still is uncertain - and the canopy indeed makes some difference - i'l concentrate on a few other issues. First of all the back idler close to the swing arm. It has been problematic for years - see my explanation in post #14.
Here a rough sketch of the situiation - the positons of the two idlers are not exact, but thee do demonstrate the situation:
There have been rumors around that the idler in the back could be taken out not only without disadvantage but even be an improvement (these rumors concern the 3 modified for racing i showed several times).
Here is an old simulator showing the situaton for a different well known velomobile of that time, the Quest:
https://web.archive.org/web/20200312...tml?bike=Quest
It turns out that the situation i a GoOne 3 with the 2nd idler removed should be very close to the numbars given here, even (very) slightly better if You enter the correct numbers for my bike but with just one idler. One condition has to be met, however: the suspension element i the back must be adjusted to a sag of 30%. Otherwise the chain far away from the axle, and the suspension would pump, or in case of a blocked suspension the chain would glide on the slot in the body of the velomobile (or on the chain hole in the swing arm), even if You enlarge it.
The nice thing is that the chain will run almost perfectly through the axis of the swing arm when on the slowest gears, and in the mostly used gears the positive and negative effects of that mod (less friction on the idler vs increased losses due to pogo) mostly seem to cancel out.