I’ve been doing the unicycle for about 3 months now and I can hop up kerbs on it. However, I see videos of people hopping onto cars and wondered if it was just practice or if you needed a special unicycle/tyre to jump much higher?
For high jumping you should have a trials unicycle (very sturdy and hopefully not too heavy) with a nice fat tire (very bouncy). Otherwise, depending on your body weight, your unicycle is likely to crack up pretty quickly. And, yes, practice!
If you search this website, you will find tons of stuff about hopping seat-in or SIF, high jumping records, side-hopping distances, rolling hops, riding down the stairs, etc.
check out the ‘Ryan Atkins’ Jump high tutorial on you tube.
Also, try using a ‘Monty Eagles claw’ tyre on your uni. But first check that your wheel size is compatible with it.
Lastly, use tyre compression to get airborne. Don’t damage your wrist by pulling up too hard as you jump, focus instead on getting optimum tyre compression.
Hope this helps.