I was going to take a friend out for a first try. I think I should cut this seat post down for her though -
Question is, if I know the floor-to-crotch with shoes measurement - what should I start with for pedal axle to top of saddle distance? e.g., should I subtract an inch, 2 inches … ?
I had never done that measurement before but I just found something interesting.
Measuring crotch to floor with shoes on, then my unicycle from bottom pedal to top of the seat. The unicycle measurement is actually about 1 inch longer. Probably because I ride with the balls of my feet on the pedals.
My advice based on that would be to cut the seatpost so at it’s lowest setting the distance from the bottom pedal to top of the seat is equal to her crotch to floor with shoes on measurement. That should give some leeway both up and down.
For a beginner, set the seat as you would for a bicycle and then lower it an inch.
I have had problems lately, and resolved them by lowering the seat a little.
For learning with a handrail, I found I could balance better with my legs at full stretch while pedalling.
However - once I was in open spaces away from the safety rail, UPD dismounts became more frequent and hazardous.
My problem was stepping off when the seat was too high.
I just couldn’t clear the saddle to get off, and came down a like a ton of bricks.
1 or 2 inches short of full stretch will allow the learner to dismount safely.
Expect to move the seat position around until it feels correct.
Shoe thickness will make a big difference also.
Before cutting off any seat post, make sure you don’t need the extra length. As my riding progressed, I raised the seat post a considerable amount. If I had trimmed too much off it, early on, I might have come up short, later.