What Chris said.
Adding the road riding and you can go slow too… ya it’s the ride of choice for me.
It’s cool going back to the plus sized 29" and it feels like a bitty wheel that’s so easy to personhandle.
But of course, you have to go through several of the sizes in the learning curve to settle on one.
If I could only have one it would probably be a 29". But I’ve never ridden a 29", so maybe I wouldn’t actually like it 
.
(Instead I have both a 36" and a 650b, but every now and then I do consider paring down to just a single 29".)
Right now, it would probably be 27.5", it’s my do it all Muni and I love it. In the past, it would have been a 20"x2.5" for Flat/street/freestyle.
I’m always toying with the idea of downsizing to just having those two. Right now I have a 19" and a 20" freestyle and I honestly don’t like having to choose between those, or adapting when I switch. Probably sacrilege to say this on this forum, but N-1 might actually be a nice solution for me currently…
When I was looking for a uni I was trying to decide between 27.5 and 29. They are actually so close in tire circumference that it doesn’t really matter which one you choose. A “29” er is actually a 28. 29ers in the mountain bike world we’re being surpassed by 27.5 but that is changing again as ebikes arrive on the scene, there is a resurgence of 29ers. I think there will be plenty of choices for tires for a long time.
Anyway I would choose 29 if I could only have one.
Lots of awesome feedback! Thank you. I am still learning but will soon hit the “buy” button for a 29 nimbus in January hopefully. 29 seems to fit with what i am after. Likely 70 percent paved river trails and 30 percent trail riding.
I remember this question being asked ten years ago, and the whole idea was somewhat frustrating for me 
Cheating slightly by suggesting one frame with two wheels.
Probably a 26 with two wheel wheels for road and trail. 26 is kind of the biggest of the small wheels or the smallest of the big wheels. It is fine on the footpath (sidewalk) among people.
Or maybe a 29 with a 29 road wheel and a fat 27.5 wheel for off road. The 26 wheels would fit that frame as well. And 24 and 20 wheels too.
Having one frame and six or more wheel is still technically one unicycle.
I can’t decide between the 29" and 36". One wheel ONLY (no pun indented) I would say 29", but most of the time I ride the 36", the big wheel it just more fun.
I think we should have a proper Poll on this. No cheating or bending of the rules 
I’m not an experienced unicyclist, but 27.5" is my favorite size. Not too big, not too small, fine for city and off-road rides.
I have 24 ,29, 36 and think 29 would be my choice for having just one .
A 44" wheel with a pneumatic tire.
If you could only have ten unicycles, which would you choose? Probably a more realistic question for you 
Ahah, that’s easy!
And maybe one or two unis to initiate friends 
I think this is the surprising thing to me because you run the store of knowledge for our sport.
Only one? I’d say 29". Two, then it would be a 24" and a 36".
I have an interest in web stuff, information preservation on the Internet and I’m a “Sunday unicyclist”. Hence I updated and I took care of forum.monocycle.info and unicyclist.com
But I’ve always ridden alone (nobody rides in the various places I’ve lived in…), I’m kind of an outsider/loner, sort to speak
I don’t even know how to ride backward, idle for more than 3 seconds, or jump on sidewalks. It has been on my to-do list for about 10 years and counting.
You may not be able to ride backwards but you sure do a nice job on running the forum. Thank you for all of your hard work
I’m with everyone on the 29" being my only uni if I had one. At my peak I had:
Currently have a 29 x 3.0 with 100/125/150 cranks & a 24"
24" is great for getting around the neighborhood or visiting friends. 29" is for Unipacking, muni, and just getting around town. I built the 29" to be a do it all uni so I’d stick with it as my only uni.
I’ve seen a geared 24 be equivalent in speed to a 29" though so maybe it or a g26 for more tire selection.
I only really need 5 unicycles:
2 x 36
1 x 29
1 x 27.5
1 x 26
A fair question would be which one I can do without if I have to. Probably 27.5
I know bending the rules is a bit of a unicyclist habit with these kinds of questions - about the one essential unicycle.
I do however feel that 36ers (and I guess 32” wheels) are in a class of their own and outside of the 24-29 realm.
This means that I do feel it would be better viewed as:
Which unicycle from 24”-29” would you have to ride, along side a 36”.
To my mind the following wheel+36” combo can never be bad choice/combo:
Combo A 24”+36”
Combo B 26”+36”
Combo C 27.5”+36”
Combo D 29”+36”
Why do I view it like this?
Well I think any of the above combos give the fullest experience of riding unicycles - and that comes from the fact that a Big Wheel ride is just completely different and separate to the other sizes.
I’m guilty of feeling I need a ton of different sizes. And there is a reason for owning each size. But it’s all about subtleties once you’re adding in wheel-sizes beyond one of the wheel+36” combos above.
I’d suggest the 36” is viewed as a massively different experience to all other wheels.
If I was new to this sport and was advising myself where to start I’d map out Combo D:
I’d say to myself:-
“First, Felix get a 29er and get really good at riding all sorts of trails. Towpaths, roads, muddy tracks etc. Then for your second wheel - because, there will be one more - get a 36er. Job done….”
Any wheel got after this is unnecessary but won’t feel like it is. That’s a different matter. The maximum unicycle experience I posit is achieved with any of the two wheel combo 
*NOTE: I’m not including smaller wheels - trials and the like as I don’t use that size and would suggest they’re in a space of their own, much like 36er
