first sorry for my bad english, second I decided to buy new 20’’ unicycle I want KH but for now it’s to expensive for me, but QU-ax seems like a good choice. I was thinking about Qu-ax 20" cross (with red hub) because price is ok and i think for starting to jump and drop it is good choice. But now i was wondering after some time can I upgrade hub with Hub - Qu-ax Splined 48 Hole (yellow one) or some KH hub or nimbus or any better hub?
If you are begging with jumps and drops then the Cross/red hub should definitly be strong enough for you; and a good choice for the price.
Yes you can upgrade to the yellow hub with it no problem (KH hub has different amount of spokes).
The only problem, I think, is the Cross has a 20" BMX style rim and to upgrade to a trials tire you need a new rim too (“Real” trials tire is really 19", must have a 19" trials rim). But, you can always upgrade a rim too if you ever need it.