I recently purchased a KH20 and have been having a lot of trouble riding down stairs. I can go down 3-5 stairs easily on my 26" hatchet when I use the brake, but I want to learn to ride down stairs w/out braking.
Tried a 3 stair yesterday and after I rode down the first stair I bounced off the seat and got posted up for a second until my uni shot out from under me, crushing my balls and dislocating my shoulder. I don’t mind taking a mild beating from time to time, but I would really appreciate any advice on how to successfully ride down stairs. Been riding every day possible for about 2 months now, and I am seeing a lot of improvements, but stairs, and riding off of anything higher than about a foot has been very difficult.
Here is a highly inspirational ancient thread on this topic.
I have now learned to sidehop down an unlimited number of stairs and keep it all one hop per step, but I have always been a bit cautious about actually rolling down the stairs. 2- and 3-sets are the best I’ve done so far, unless you count some extremely gentle stairways, and I’ve only done this on my 20, never anything larger.
Making sure your feet don’t come off the pedals seems like one of the most important things. From the accident you describe, it sounds like you might also want to lower your seat a bit.
Hi there
I am currently learning to ride down stairs myself in a Trials Uni and if you follow the advice given in the forum you should be able to do them in no time. At the moment I am riding down stairs with 5 steps no problem. For the first couple of tries I found it helpful to keep one hand on the saddle and the other on the hand rail: this way you get a feel for it without taking too much risk of injury when falling off. Also in the beginning try stairs that are quite shallow. As far as I can tell: I think the key thing to remember is to ride down standing up (keep your butt away from the saddle), medium speed, and try not to lean forward/backward too much. I am using 145mm cranks (not sure if that helps me to keep the Uni under control better than using shorter cranks?)
Good luck hope the above helps 
I have moved on to less extreme things after being a little more adventurous with trials when I was younger. The thing I found helped me learn was a deep tread set of stairs, when I was learning I’d go diagonally down as to have it feel more like dropping off a bunch of curbs in a row. As I got comfortable I’d take a more agressive angle until I was going straight down, after that it was onto harder stair sets.
Obviously everything above applies, keep your weight off the seat.
Good luck!
If you hit the ground with your wheel rolling, you will significantly reduce the impact on your body and your unicycle, so if you sidehop off of something, twist in the air so that you are traveling forward rather than sideways when you land.
Experiment with the tire pressure.