Question #1
In this video http://www.youtube.com/watch?v=1uPznTbus3g , what size tire is Kris Holm riding?
Question #2
How big of a defference is it between a 24 inch and 26 inch tire?
Question #3
Is a Qu-Ax 24 inch mountain unicycle a good buy for the price?
http://www.unicycle.com/shopping/shopexd.asp?id=796
Question #4
How much heavier is, specifically, the Qu-Ax 24 inch than the Qu-Ax 20 inch trials?
Question #5
Does the 24 inch work ok for trials-like stuff?
Thanks for your help,
Jeff
It looks like a 24 x 3, probably a Gazz.
2 inches. Duh! 
My 26 x 2.6 Gazz muni is only slightly larger in diameter than my 24 x 3 Gazz muni. I pretty much never ride the 26 anymore.
Yes, it’s a nice uni at a good price. It’s heavier than other options like a KH, but not horribly so–maybe 2 pounds difference.
Can’t say specifically, but generally there’s about a 3-lb gain from a trials to a muni of similar models. Probably something like 14 trials, 17 muni.
It does okay. I don’t have a trials uni, but wish I did when I go out and just “play” on steps, benches, and so on down at the local park. The 24" is a great muni, but I think I’d be able to hop a little higher on a 20". It all depends on what you plan on doing most–I’m more of a muni guy, and see the trials-y stuff as useful in getting me through the trail with fewer UPDs.
Thanks alot for your help. Your input has further solidified my decision on getting a 24 inch over a 20.
Sorry about the stupid question about the different between a 24 and 26, I meant that in how it feels, not the difference in measurement. 
The Qu-ax 20" is 14.08lbs; their website doesn’t list the 24"s weight. I think between a 20" and a 24", you’ll get burnt out sooner riding Muni on a 20" and likewise running trials on a 24"-- But it seems like Qu-ax was trying to accomodate both with these uni’s: longer cranks on the 20" and 48 spokes on the 24"-- anything with a fat tire should work…
I’d vote Muni, get the 24" Qu-ax or use the money to buy a wheelset, frame, seat and seat post.
I always thought the real difference between a 24" and a 26" isn’t size, but the variety of tires that the LBS keeps for the 26".
Muni has more or less standardized on the 24 x 3" wheel for the more aggressive style of riding. That is the style that involves plowing over roots and rocks, going over drops (small or big), jumping over or on things, and even the more tame XC. The 24x3 is just a convenient size. The 3" tire is like adding a suspension fork to a mountain bike.
The 26 x 3" wheels get to be heavier and less maneuverable. Less convenient for the hopping around. It’s more suited for cruising on a trail than playing on a trail. It’s also heavier than something like a 29er. A 26x3 is more of a niche size for someone who knows that’s the size and style of unicycle that they want.
29ers are for XC. Faster and lighter. The skinnier tire makes them more maneuverable than a 26x3. The lighter weight makes them more nimble. They’re for XC style riding. That is cruising an XC trail and not doing a lot of jumps and drops. They can be ridden aggressively but you have to know the limits.
So in general there are two sizes that have become standard for muni. The 24x3 is for the more aggressive style of riding mixed with some XC. The 29er is for more pure XC. Then some like to throw in some Coker muni just for kicks.
You can do some trials style riding on a 24x3 muni. You can jump on and off things. Ride skinny things. Do rolling hops. Not as conveniently as on a 19" trials uni, but not a huge restriction. I take my muni out for trials style riding at times. I’m not much of a trials rider, but the muni still keeps it fun. Kris Holm used to do trials riding on 26x2.7 and then 24x3 before the 19" trials unicycles became available.
If you get interested in the more pure trials style riding or street style riding you’ll end up wanting to get a 19" trials unicycle for that. A muni is more suited for trials style riding than a trials uni is suited for muni. Muni on a trials uni is not even close to the same experience as muni on a proper muni.
The other variable in muni riding is crank length. Recently there has been more of a trend towards shorter cranks for muni with a 24x3. Old-school is the 170mm length with a 24x3 wheel. Trends now are for lengths in the 165mm to 150mm range for muni with a 24x3 wheel. Crank length is in large part personal preference and what’s suited for your body size and riding style. The Qu-ax muni will limit you to the 170mm length (or 145mm length which is really short for most people).
How does riding a treaded unicycle on even surfaces feel? The tire is of the unicycle I’d like to get is 3 inches, so I’m wondering how this will be different than a normal tire.
Similer to riding a bike with a treaded tyre just a little vibration;)
The 3" tires all feel pretty bad on hard surfaces, especially if you’re running them at MUni tire pressure. Squirrelly and slow.
As usual John pretty much nails it on the head. I would add the following from my personal experience:
I like the 26" wheel size a lot. I am fairly tall (6ft 2) and finds it works better for me. However I like playing on a trail and a 26x3 is indeed a cumbersome beast. When I first tried a 26x3" tyre I found it rode like a tank, it really was an effort to turn. I am now back to riding a skinnier 26x2.45 (Hutchinson Jumbo) and this brings the behaviour of a 26" more in line with an XC unicycle with the bonus that I can still confidently bomb off big drops and use it to attack aggresive trail riding.
The difference in diameter between a 24x3 gazzalodi and the 26x2.45 hutchinson is not that large but I still prefer my 26. It is, as John says, a niche unicycle and if you are an aggressive rider you definitely have to know that a 26 is the size you want. There are virtually no top of the line 26" munis availlable off the shelf. Upgrading a Nimbus 26" to a KH moment hub is probably a good option if you want to experiment with a 26 and then decide you need to beef it up.
I think 26" is a great size. It’s the standard MTB wheelsize so you have the greatest choice of rims and tyres to choose from. You can go tubeless relatively easily because the rims and tyres are readily available.
It works very well of XC- I’m gone back to using my 26x2.6 with 150mm cranks and I much prefer it to my 29’er and 24" for general MUni riding. A 24" feels too slow, and 29" tyre’s are mostly too skinny to ride fast over bumpy terrain. And there are hardly any tyres and rims to choose from in the 24" and 29" sizes.
Really? A tubeless muni setup? 
I thought that was a road cycle/XC thing. Do you get a big momentum boost from the weight loss?
Tubless is great on Muni.
You dont have to worry about pinchflats, or the heavy DH tubes to resist pinches and thorns.
The weight savings make it feel a lot better to ride also.
There was a nice link that talked about Muni and mountain biking with a tubeless set-up.
Ill try to find it.
The other variable in muni riding is crank length. Recently there has been more of a trend towards shorter cranks for muni with a 24x3. Old-school is the 170mm length with a 24x3 wheel. Trends now are for lengths in the 165mm to 150mm range for muni with a 24x3 wheel. Crank length is in large part personal preference and what’s suited for your body size and riding style. The Qu-ax muni will limit you to the 170mm length (or 145mm length which is really short for most people).
I’m 6’ 1" and 145 pounds, is the 170mm an ok size for me?
How is a 150mm different than a 170mm in how it feels and functions?
Riding with 150mm is somewhat less wobbly. 150mm is noticably faster and takes less energy on easy stuff (fire roads). 150mm gets fewer pedal hits.
150mm has slightly less leverage; it’s a bit harder to slow down on extremely steep stuff, or after drops. It’s not as easy to hop with 150mm.
Overally, the difference is fairly subtle. I plan to switch back to 165mm for Moab, but I rode with 150mm at California MUni Weekend and did just fine on some gnarly terrain. I think the trails you’re likely to ride are much more important than your height or weight; if you’re doing a whole lot of steep up and down with big drops (like the LA/Santa Barbara guys), you’ll appreciate the longer cranks. If you’re riding a fair amount of easy stuff, your rides will be more fun with shorter cranks.
There some rides in the Santa Cruz area which have some really fun technical downhill, and a lot of boring uphill fire road getting to and from the fun part. I would much rather ride the technical stuff with 150s than the boring stuff with 170s.
If I ever want to switch to 150mm cranks is that possible with this unicycle?
Municycle.com (the German branch of Unicycle.com) has a better selection of Qu-ax parts. Check there to see what other crank lengths Qu-ax has for their splined hub. Here’s the Qu-ax splined cranks. They are available in 127mm, 145mm, and 170mm.
At your height your legs will be plenty long enough to comfortably pedal the 170s. Shorter people find the longer cranks more ungainly than the tall people.
Crank length has a lot to do with personal preference, riding style and what you’re willing to get used to. With the longer cranks you have to concentrate more on pedaling in circles and pedaling through the bottom of the stroke so you don’t lose your momentum by stalling slightly at the bottom of the stroke. Takes practice but isn’t a hindrance once you know how to pedal that way.
Some other brands of unicycle have more choices for crank size, but they’re also going to be more expensive. Balance the cost with how much you think you may experiment with crank length.
I believe the bicyclists use 170 as a standard size crank.
That’s because bicyclists have gears, and thus don’t need to care about crank length very much.
I use 170’s…
The torque is nice and it feels natural making a larger circle.
Trials on a 24
It is definitely possible to do trials on a 24, infact, I do trials exclusively on a 24" muni with a Gazz. I used to have a 20" trials but i gave it away because i never used it.
Heres a really short VIDEO of me on a 24:
http://www.unicyclist.com/index.php?page=gallery&g2_itemId=203484