If you are 50 or older, have you considered riding a recumbent trike? These are 3-wheeled bicycles, that take most of the pressure off your tailbone. - Quora
KMX+Recumbent+Trike For Sale
TADPOLE TRIKES FOR KIDS – Tadpole Rider
KMX trike build (updated pics)(new HD video) | Page 4 | Endless Sphere DIY EV Forum