I have enjoyed my Nimbus 26er for nearly two years and I am thinking that I’d like a bigger wheel for longer rides. I started doing research on 29ers and getting ideas about all the options. However, in the process of my research I started asking questions about the 32". Most of my riding is on roads, so muni is not a consideration in this decision.
I have read as much as I can find and it seems that moving up to the 29er is a natural progression, but it is only 3" bigger than my 26er. Several on the forum have said that the 32" rides like a 36er, but is more maneuverable, like the 29er. I
I know that ultimately it is a personal decision and I am okay with that, but some of you have some good insights. I’d appreciate your thoughts.
My advice: Go with the 32, or go all out and get a 36 if you have the room. A 29 won’t feel very different from a 26 if set up similarly.
Eventually you end up with all the sizes anyway 
Not all tyre sizes are exact. For example, a fat 24 may have an actual rolling diameter nearer to 26. However, if you take the nominal size as accurate for the purposes of illustration:
24 is 4 inches bigger than 20, which is 20%. A big step.
26 is 2 inches bigger than 24, which s 8.3%. A small step.
29 is 3 inches bigger than 26, which is 11.5%. About the same as one tooth change on a derailleur bike.
32 is 3 inches bigger than 29, which is 10.3%. A very slightly smaller step.
36 is 4 inches bigger than 32, which is 12.5%. A decent step.
Compared directly to 29:
32 is 10.3% bigger.
36 is 24% bigger.
So, yes, the 32 is very much a half way house between 29 and 36. However, the 10.3% difference in diameter, and therefore speed at an identical cadence, is only equivalent to changing about 1 gear by 1 tooth on a derailleur geared bike. (Slightly more, but same ball park.)
Set against this, the 29 and 36 both have a wide range of tyres.
Now think about seat height. Assuming a standard riding position, the height of the seat is determined by two things: the height of the hub above the ground, and the length of the cranks.
The height of the hub above the ground is related to the radius of the wheel. The 36 has a 4 inch bigger diameter than the 32, so a 2 inch bigger radius. With the same cranks, the seat of the 36 would be 2 inches further off the ground: 51 mm.
With a slightly bigger and heavier wheel, you might choose to have cranks that were slightly longer, in which case the seat height would be reduced accordingly.
Using these principles, the 32 seat would be not more than 1.5 inches (37mm) higher than a 29, and the unicycle would be about 12.5% faster. If you normally ride at 8 mph, you’ll be riding at 9 mph.
Personal opinion, but I think that 32s exist only because the tyres exist and someone had to try it. If you want big, go big and get a 36; if you want nimble general purpose, then go for a 29.
Some people may find that a 32 exactly hits their sweet spot, but with a 29 and 36 in my fleet, I see nothing that a 32 would add.
it is not a question about 29" OR 32", at least when your 29" is muni. Then it is about 29" AND 32". I had my 32" after the 36", mostly because I wanted something easier to mount and still be faster than a 29". It turned out the 32" is a very good road uni and very flexible in turns. It isn’t as heavy as a 36". My Nimbus Oracle 29" muni is very different from the Nimbus 32" and I like them both for how they ride.
It’s also, in my case but not only, the last size that’s easy to freemount - whether you’re into the rollback mount or the static mount. I can only do a walking rolling mount on the 36".
I’ve put many miles on a 26x3" (mostly on dirt) and a 36" (a mix of easy dirt and road) over the last ten years. For easy path riding, I found that the 26" is too slow for me, requiring too much spinning to be fun. And while the 36" is fun, for me it can be tricky to safely maneuver around people and dogs (on or off leash), and I got annoyed with having to dynamically remount with people and dogs around. I also found that I was being silly in trying not to dismount at road crossings, which was dangerous. So I got the 32" early this year.
For me, it’s just as fast as the 36". I don’t like to go so fast that I spin out on the 36", so there is easily room for spinning about 10% faster on the 32" to compensate for its smaller diameter. I can ride with my wife on paths when she’s on her bicycle, and I’m actually still faster on inclines.
The 32" is as easy to static mount as the 26". It’s still easy to mount after many miles of riding. With the 36", I can get too tired to mount reliably.
The 32" is not as maneuverable as the 26", but it’s much more maneuverable than the 36". It has some of the “big wheel” feel, but not the “wagon wheel” feel of my (heavy) 36".
I’ve never ridden a 29". It’s probably fun, too.
I love the 32". I think it’s the perfect size for me. In my opinion, it should be the default “big wheel,” with the 36" more of a novelty wheel for people who want maximum ungeared speed. I might eventually start riding the 36" again just for its unique feel, but I’m sure I’ll always be grabbing the 32" over the 36" when I want to ride any distance, or on dirt, or around people.
Thank you for your insight and your opinions. It helps me to talk about it to folks like you who have experience in the world of unicycling.
Thanks again!!
I think I agree with Sasquatch; 32" because 29" isn’t much of a difference.
I have lots of unicycles, from 12" to 45", but not a 32". I’ve ridden one, and it was great. It felt more like a 29" than a 36" like others have said. I think you should get one of those, because I don’t have one. 
That’s a perfectly normal, if not the default, mount for a 36" or larger. Static or rollback mounts would both be extremely awkward!
You should try an actual wagon wheel unicycle. I’ve been exposed to a couple of those, one of which belonged to USA Founder Bill Jenack. About 42" and 42 pounds (at least). Now that’s a wheel with some momentum! Great once it’s rolling, but generally more tiring because you’re hauling around a bunch of extra rotating weight. But the looks are killer!
Then there’s my old 45" uni, which weighs about 28 pounds. Steel rim, solid rubber wheelchair tire, cottered cranks. Hey, it’s from 1982! Still the best parade unicycle there is. Great for spins and quick turns, but also to get you back to the car when the parade is over.
I have a 32" Oracle and a 29" Oracle. I got the 32" first just because it was a very good deal. At the time “my next uni” was going to be a KH 27.5. I then bought the 29" Oracle second hand on here as it was a good deal too. At that time “my next uni” was going to be a KH 27.5 
I like them both – I like the 29" more for off road and the 32" for the road. I’ve ridden the 29" on the road but prefer the 32" for that since it has a bit of a different feel, some of it is maybe psychological since you know you are on a bigger wheel which is a bit out of the ordinary. It is a pretty nice looking unicycle as well. I’ve never ridden a 36" so I can’t comment on how the 32 rides compared to that.
I found the 32er pretty easy to freemount straight away just coming from a 24" muni, I was quite surprised actually.
The 29er fits in the back of my car more easily than the 32", so that may be a consideration if you need to transport it.
Also, regarding just going for a 36er instead of the 32" – I am 5’ 7" so I always figured a ‘conventional’ 36" (ie. not a Nightfox) would maybe be too big for me, so the 32" seemed like a good idea for a dedicated road machine.
My current “my next uni” is a KH20 to learn some new skills, so that probably means I’ll buy something completely different 