Ahhh… I see what you mean. That’s the same reason I was thinking low pressure would be better, more springing distance. But I was basing that on my jumping abilities, which are not very powerful. So a lower tire pressure works for me, because if it is higher then I can’t compress the tire. But of course, if you are powerful enought to actually compress the tire at higher pressures, then that’s the way to go.
It’s timing not strength. yes, many of the high hoppers are strong, but anyone can do 32" with enough practice. I’m not strong at all (ask anyone who’s met me in person), but I’ve learned to time my kicks to compress the tire as much as possible. I can’t totally explain how to learnt he timing, or how the physics of it work, but I know it works.
Re: How the hell do u hop so high?
LEARNING PHYSICS HELPS ME UNICYCLE 
please read all this, It does make sense:
F = ma
(force is mass times acceleration),
Acceleration is the change in velocity over time,
so. F = m.(v-u)/t
and therefore F = ( mv - mu ) / t
ie: “force equals the difference in momentum divided by time.”
*** and so force multiplied by time = the change in momentum (delta p)
which shows that to increase the change in momentum (the amount in
which you hop), you can either:
- increase the force - ie: jump harder and with more strength. or,
- increase the time your downward force acts. ::: (this is leading
somewhere I promise!)
Point number 1. is obvious, but with 2. I think that to increase the
time, you can have your tire at a lower pressure - which means that
because when you jump, the tire is in contact with the ground for
longer than if it had a high pressure (imagine bouncing a squashy
marshmallow as opposed to a rock) - and so the force pushing you and
the unicycle up from the ground is acting on the floor for a longer
period of the time, by my knowledge of physics (i’m only 16), you
should go higher!
to what degree… I know not.
[but on the less physicsy side, I’d say hop seat out and practice the
correct technique. After that it is just a matter of strength.]
Re: How the hell do u hop so high?
I’ve also just realised that the air pressure inside the tire increases
the FORCE of it.. so you have to get the right balance between the
time, and the force. I reckon to have the tire pumped relatively low,
but not so low as it hits the rims. just enough so it can squash right
down nicely against the floor and then spring back up with the force
you push down with using your legs, coupled with your upper body’s
momentum (swinging arms up) and also coupled with the spring on the
tire.
Be wary of the Gerble. He may not have a crushing handshake but he’ll hop over your head and kick you in the a$$ before you know it! This dude FLIES like he’s Jackie Chan or something. I saw him rolling hop up a 12 foot wall once.
Seriously, follow the words of the Gerble. He is the Yoda to my Luke Skywalkerage. And he will teach us all to harness the force of the tire. My rolling hop increases by several inches every time I ride with him.
Re: How the hell do u hop so high?
I absolutely don’t believe you atall..
it’s not possible to rolling hop a TWELVE FOOT TALL WALL!
I mean, that’s like the height of two very tall people on top of each
other.
it’s not physically possible to jump that high without a unicycle,
let alone with the weight of the unicycle to lift up as well.
Plus I dont believe you can hop over someone’s head when they’re
standing up, unless they’re very small. the biggest hop I’ve ever seen
is only just past a metre high (around 4 foot) kinda thing, otherwise
it’s just not physically possible.
Answer to above post.
When Meastro says “you”, what he really says is “yall midgets and unproportionatly short people out there”
You exaggerate so bad. Dude, that was only 9 1/2 ft wall.
Before we dive into the physics, I’d like to state that no amount of physical analysis will produce a better unicyclist. It may help produce a better unicycle (or component thereof) but riding is something you develop a gut feeling for, it’s not a set of equations you’re solving on the fly.
Your physical analysis is leading you in the wrong direction. One cannot simply “compress the tire for longer”. Keep in mind that, when jumping, you’re accelerating away from the ground. As this happens, it becomes harder to apply the same force on the ground. You’d have to push harder and harder with your feet while you’re leaving the ground!
Standing on flat ground, if you “push down” on the ground with your feet, you’ll get an equal and opposite reaction: your body will rise. If you push “fast enough”, your body will accelerate upwards and overcome the acceleration of gravity: you will briefly leave the ground. Reinterpreting Newton’s second law (F=m*a) in terms of momentum, we find (F = m * dv / dt = dp / dt) that a greater change in momentum can be achieved by applying the same force in a shorter amount of time.
If anything, your argument is proving that one should try to compress their tire as quickly as possible to achieve their maximum hop height. But as I’ve said, physical analysis is hogwash. Practice and advice from fellow riders are the only solutions to the problem of obtaining higher hops. We’re humans, not robots, so equations (which are oversimplified models of reality) are meaningless when it comes to cleaning a bodacious trials line!
Thanks for the clarifications, I actually meant “y’all unproportionately short people under 9 1/2 ft out there” when I said “you.” 
Gerble is teh Jedi master.
No no, I saw Gerblefranklin clear that 15 foot high wall with my OWN two eyes!
I saw the same thing, but I used someone else’s eyes.
Uhhh, ok…
I agree with Jason on this, physical analsis is useless here. I apply physics where I can, but it does nothing to help me ride. A hop on a unicycle is simply too complex to analyze and explain using armchair calculations. F=MA is a useful equation for rigid bodies in generally linear motion, but when you’re dealing with something as complex as a unicycle hopping, you’re wasting your time, unless you actually want to know the answer, rather than just ride.
One last thing, I didn’t air that wall, it was only a pedalgrab…
I agree with everything that Bevan said… Unless he said I was stupid. In wich case I wouldn’t agree with him.
Watch and learn…Monkey see monkey do…Btw I love how you tittled this…
Re: How the hell do u hop so high?
“We’re humans, not robots”
Speak for yourself dude!
Come on Maestro.. anyone who uses the word ‘bodacious’ in 2005 can’t be
taken too seriously..
No-one’s said bodacious since Bill and Ted, everyone knows that.
But yeah, you’re right.. I mean from when you said:
" that a greater change in momentum can be achieved by applying the
same force in a shorter amount of time. "
So if you apply a force of 100N downwards for 1 second, that gives a
greater change in momentum that 100N in 10 seconds.
But you might need those extra seconds in order to bend your knees and
get right down so as you come up you can continually push down with
your legs and you have a high acceleration.
… But this is a little bit irrelevant, because we were talking about
tire pressure as far as I remember.. so the tire should be pumped up as
much as possible (so that the tire still compressed) so that the
maximum amount of air pressure is utilised to help with the hop.
I was just doing my best to explain things with physics, because
someone said that they didn’t know the physics of it.. so i thought i’d
have a go. big deal!
lol
i totally use bodacious all the time. but, i don’t know if people take mer seriously or not. except for halloween, when i was seriously serving real ice cream (i was an ice cream man!)
It’s true…I’m a skinny little borderline vegan, and I can get 32" without a prehop!
The higher pressure folks, has to do with the sidewalls. I run a Maxxis at about 40 right now. I hate that piece of crap tire and it’s thin sidewalls. But, no worries. I’ll be through with it due to wear in about a month or two at the most (and I’ve only had it for LESS than a month). But the Luna is ideal for what gerble is talking about.
More pressure=Larger force need to compress=larger rebound…at least that’s what I’ve noticed from experience.
If you run with too LOW psi, you risk folding over or bottoming out for almost every trials situation.
later,
Evan
haha… tittled:D
thats fun to say!
I use “bodacious, hecksa fresh, cutty,” and various other terms all the time. Don’t take me seriously, fine, but you’ve got nothing to gain by doing so.
Nobody said they didn’t understand the physics of it. Jason just finished with a physics major in college, so I don’t see any reason to be arguing with him on the topic if you feel the need to accompany your solutions to basic equations with a disclaimer.
32" without a prehop is fun. When I do things like that without a prehop, there’s that weird feeling of only having the outer row of knobbies clinging to the edge of the object.