Muni wheelsize discussion thread

There are lot’s of things to choose from nowadays: wheelsizes from 24" to 29" with increments of 2" or less. Tire sizes all the way up to 4"(+?). How should anyone decide between that many options? I felt like there should be a central thread to discuss that question, forgive me if there already is. It should not really be about different models and brands, more about what size of wheel and tire to choose in general.

Here is my reasoning for a recent purchase:

I bought a new Muni, and it’s neither a fatty, nor a 27.5".
So there have been many good post of people explaining why they bought a fatty, so I thought since I just obtained a 26" Oracle, I might explain why I went with the smaller tire, maybe it will help someone with their decision (also I have stuff for university to procrastinate… :smiley: ).

So a really short background on my unicycle history: I mainly ride flatland and street (street unicycling= grinds, tricks down stairsets etc., not riding on the street, I feel some people newish to the unicycling world confuse that) right now, used to ride a lot of trials (and there was a bit of track racing/freestyle, too), but recently the downhill bug has bitten me. I tested a fair few of other peoples Munis of different sized tires at different occasions before deciding I needed one myself. My choice wasn’t specifically on an oracle before one was on sale used for a reasonable price, this is more about why I chose to go with a 26 with a ~2.5" wide tire, which I had decided on before the oracle popped up.

I not very tall (1.71 m) and I have even shorter legs, so even a 24" uni for me might proportionally well be the same as 26" for others, and I am very used to 19" which feels almost like an extension of my feet now, so a smaller wheel is closer to that feeling. (26" is more or less a requirement now for keeping up with other when riding now though, so a smaller wheel was not an option for me.)

A wider tire does not necessarily mean more grip, in my experience grip in all but very loose sand or deep mud is very similar, and well, sliding can be fun. The increased rolling resistance of a wider tire bothers me a bit on flat sections though, while the weight isn’t a big issue for me, if I had gone with a custom setup I would’ve had a 48h rim for that extra peace of mind.
I like taking obstacles aggressively, like turning in to hit a root 90° where the bigger wheels just don’t react as fast, or rolling hopping over stuff (a lot), where extra wheel size just is a disadvantage. For me, the great thing about being on a unicycle is it’s maneuverability. I can turn 90° on a dime, and if I want to be a meter further left, I can hop there easily, and a fat uni takes a bit of that away (mainly the turning) . I am neither sure what is faster, a wider tire and rolling over stuff, or a smaller tire and more actively taking the terrain, nor am I really sure I care, for me, the latter is just more fun, and that’s what it is all about.

That’s my reasoning for my decision, feel free to discuss and share your arguments for your decision, or just thoughts your in general, I am sure they’ll help someone make their decision.

My mUni is a 26" Oracle with a ~ 2.5" wide tire.

I think this is a difficult conversation, because everyone rides in different conditions and at a different skill level.

Myself: roots and rocks are not generally a huge issue on my local trails. I use handle-bars, and the stability they give me allows me to ram through some stuff that would otherwise require a fat tire. I dislike the sluggishness of a heavy tire, and prefer responsiveness over momentum/inertia. I hop sometimes when things get tough; I appreciate a lighter tire for that. I run 165mm cranks on the 26".

I think some of the information that could follow in this thread has been covered in the tire reviews; people talk a lot about their preferences and riding conditions in those threads. I always appreciate embedded links to other threads which are on-topic.

I have used a variety of wheel sizes and tire widths over the years, including one-off handmade/modified tires. Off the top of my head I have used:

24x2.3, 24x3.0, 26x2.1, 26x2.3, 26x2.5, 26x3.0, 26x3.8, 26x4.0, 27x1-1/4, 29x2.1, 29x2.35, 29x3.2, 32x1.75, 32x2.0, 32x2.4, 36x1.9, 36x2.25, 36x2.4.

They all had their advantages and disadvantages, I currently mostly ride tires around 26x2.3-2.5. I find mid-width 26" tires with 137mm cranks to be one of the most versatile setups that handles a wide variety of trails and conditions fairly well.

I wrote up an overview of wheelsizes. but it’s in german. Maybe google translation may help you.
Translation via Google
I also made a diagram for tire sizes:

Same color means same rim diameter.

As it is in german, here are the transations:
Außendurchmesser - outer diameter
Einradtyp - type of unicycle
Einsatzgebiet - application
Federung - suspension
Felgengröße - rim diameter
Geschwindigkeit - speed
Halle - gym
Kinder - children
Reifenbreite - tire width
Rennen - race
Rennhexe - race witch
Rollwiderstand - rolling resistance
Schnee - snow
Straße - road
Verkaufsbezeichnung - name as marketed
Wendigkeit - maneuverability/ nimbleness

What could also help is this graphic by Jamis:

Here’s the translated version

That’s pretty cool!
What’s the diameter of a 24" with a 3.0" Duro tire? Any idea?
(I’m wondering if a 26" with a 2.1" tire would fit in a KH24 frame.

Standing next to my old MTB (26x2.2) it seems my 24x3.0 muni has about the same outer diameter

I tried a 26x2.35" Hans Dampf SG with full tread in a KH24 frame and can report that it had about negative 10 mm clearance. :slight_smile: Can you work backward from there?

But 24" track racing unis do actually use 559 mm/22" rims, same bead diameter as a standard 650D mountain bike, which is what put the idea in my head to even try that. I run these tires on my commuter bike and like them so much that I bought the 700c version when I built it up my road uni. I could measure the inflated diameter if it helps any.

The somewhat used DURO tire of my old KH24 has 650 mm diameter and the clearance is about 12 mm.
My old Mountainbike has a 26x2.1 tire with a diameter of about 665 mm.
So this could be a tight fit (depending o the tread).

I f you calculate tire diameter as rim size plus two times the tire width you get pretty
close to the actual diameter:
507(mm) + 2 * 3.0(inch) * 25.4(mm/inch) = 659.4 mm
559(mm) + 2 * 2.1(inch) * 25.4(mm/inch) = 665.7 mm

I guess it could just about work with a skinny tire - I’d like to build a 26" road/city wheel for urban use, with a light tire like a Big Apple, and use it in my 24" muni when I don’t take it off-road. Having several unis in one for a relatively low cost.

Where did you find this size???

My money is on the “Frankentire” response :stuck_out_tongue: :smiley:

Correct. It is my current frankentire but I haven’t ridden the 36er in over a year.