I wrote a few days ago that there "...was a way to start small..." with pennyfarthing bicycles. It works pretty well. Not too rough on the pocketbook, either. Mind you, it takes some practice and at this point, I still struggle to not wobble the wheel too much, especially when controlling speed on a downhill. (The rear brake is more of a fond wish than a practical accessory.)
That's a 28" wheel in front and the little gadget turns heads wherever you ride it. A couple more photos and a bit more info over at Retrotechnologist.
Introduction to Sim
5 months ago