I have no difficulty in riding a bicycle when wearing a reverse Kingussie kilt, and could probably manage a horse with saddle/stirrups in the same way, sitting on the inverted pleat - but I would not ride for any length of time, I think.
When doing a lot of cycling I wear cycling shorts under my kilt - putting them on causes many eyes on stalks reactions - they are meant to be outer wear and visible, after all. Maybe it is the way the pleats shimmy which sets them all aflutter.

Anne the Pleater :ootd: