Sun Mini Fat Unicycle

In this recent post of the Nimbus Hatchet 2016 Nimbus 29" Hatchet Muni questions the owner says he finds it extremely easy to mount due to the fat tire.

I was still learning, until I broke my KH20, still trying to get away from the wall for riding and mounting. I need to have another spare small wheeled learning uni. I have another uni but the skinny tire unruly in comparison. So have it in my mind that the fat tire on the Sun Mini fat would make learning to go straight and mount without the wall a lot easier until I get the KH fixed. After I get the hang of it, will practice with the smaller wheel, and other more challenging configurations.

I see a Sun with the 20 x 4 1/4 tire available for a decent price. One thing that concerns me is that the inner tubes for it that I have found so far would cost $30 each to get shipped to me.

This price seems to be way too high. If anyone know of better prices for backup tubes?

I’ve heard these sun 20" unicycles are disgusting to ride but have never ridden one.

I learned on the nimbus 20 x 4.25 tire. After I could ride it took me several weeks to figure out how to free mount, at least 1/2 hour a day, 5-7 days a week.
Some people say it’s harder, some easier. I don’t know because once you know how to get on one, getting to free mount a different one is much easier.

Both easier and harder. Easier to mount and ride straight. Harder to learn how to turn. Easier to mount and ride a few feet. Harder to ride 100 feet.

What I’m about to say is open to debate, but my thought is: It’s easier to learn on a fully inflated, skinny tire, then later move to a fat, grippy tire…than it is the other way around. It will take longer to learn on the skinny tire, but the extra time spent will make you a waaay better rider, imho.

My advice is to lower the tire pressure on your skinny tire unicycle to the point where you’re not in danger of having a pinch flat. Then practice mounting. Then blow the tire up to full pressure, then practice it that way. Try it both ways. Play around with the tire pressure on what you have.

Mounting is hard, period. Be patient. The idea of a static mount is that the forward pressure of your body on the seat balances the backward pressure of your first foot on the pedal. A fully inflated tire is going to be super twitchy for the mounts, but it will at least be giving you responsive feedback.

But, if you want to go the other route, that’s fine. As long as you keep practicing, you’re going to get it, one way or another.

Keep practicing!

I wouldn’t worry about a spare tube. They make patches to repair tubes. The tube in my first pneumatically tired unicycle lasted for 50 years, yes half a century! I learned to ride on a hard rubber tired tricycle wheeled unicycle.


I’m going to go along with that, long as you’re on paved ground. If you’re on dirt or gravel, it changes the math a little. I will add that the easiest surface to learn to ride on is a gym floor (or similar), but we don’t all have access to that. Downside is making the transition to the “real world” of riding outside on imperfect surfaces, but if you can already ride that happens relatively quickly.

I have ridden some unis with those 4 1/4" tires and I would not recommend it for learning. To me those wheels are strictly for show. They are not very strong, and are very weird when you make turns. plus probably heavy, which is a negative when learning. Stick with ElPueblo’s advice on your existing skinny uni. Don’t go below 40 psi, though you may need more depending on your weight. That unicycle is many times better than the one I learned on!

Wow! You definitely have had better luck with tire valves than I have…

Me too, which was what I was alluding to above. Except I didn’t fully learn to ride on mine; it fell apart and I had a 3-year gap before getting my hands on another unicycle (which was a Schwinn Giraffe; don’t follow my learning path).

I started unicycle training weighing closer to 400 lb than 300 lb. I had to have a high psi tire on my skinny uni. At 65 psi I completely flattened the tire and ride the rim. This resulted in multiple punctures and shredded tubes. I also had this problem with 19" trials tires and wrecked the tube. When I over inflated the trials tire it blew off the rim shredding the trials tube.

I have since lost quite a bit of weight so I could use my KH trials, the trials tire on the KH 20 can now hold me up. I have since broken my KH, and waiting to get it fixed.

I found practicing on the KH trials far more enjoyable than on the rock hard 20" high psi tire of the other Uni. It often spits out from under in what seems to me to be faster than human reflexes can compensate for. I suspect the frame also flexes and it is like a spring recoil.

I theorize that a larger tire and heavier weight slows things down a bit, possible making it an easier learning process until I get lighter, leaner, and smaller. Similar to how some people have used balance boards and slacklines under water in their beginning stages. I wonder if anyone has used water to get the basics of unicycling down?

So if anyone can point me to somewhere I can get in a couple of tubes shipped to Canada for considerably less than $30 each please let me know. The tube in this uni I am considering is already toast and the seller says it is not repairable.

Can Amazon find you up in the Great White North? :slight_smile: This looks like it might work for what you’re asking about:
Mongoose MG78457-6 Fat Tire Tube, 20 x 4"

Thanks, I probably entered the wrong search information!

I had my worst falls as a beginner, for that reason. Once I learned how to get a hand on the seat and keep it there, my UPDs slowed down, because my body and the unicycle moved together. That’s not going to help you right now. Wear a lot of padding! Good luck!

I think you’ll still be paying about $15 shipping. No real way to work around that, unless you find a shop that can get in fat 20" tubes locally. It is sort of a niche size filled by those unicycles and kids’ fat bikes, which means you may be able to have them delivered to a store (unfortunately probably Walton-owned, if they have those over there) but pick them up free of charge. There are a couple other name brands (besides Mongoose or Pacific) such as Specialized and Diamonback that are getting into the 20" kids’ fat bike scene, but I’m not sure if you have any of those dealers close by, or how easy they could get their hands on tubes for you, but might be worth a try. This is the same tube from

That makes it $30 with shipping.

I am starting to think I should pass on this thing and pick up another Trials Uni as a back up unit to practice on instead.

Wow, those are tough unicycles! What broke on it?

But indeed, as a big guy, some of the advice we’ve been giving is probably off the mark, especially anything relating to tire pressure. A Trials tire is probably the best thing for you, and at that, one that’s made for higher pressures.

I don’t know if that would work because you can’t be too submerged, or your buoyancy + the thickness of the water takes away your traction. I’ve tried it and you just can’t go anywhere because the tire has very low traction, and your body doesn’t want to go anywhere because it has to push a lot of water out of the way.

If the water only came up to your waist, or top of your wheel it would be different, but I don’t know if that would give enough resistance to make learning easier. Like someone said above, pad up! As your skills improve, you will continue to get better at detecting (and preventing) those moments when the wheel wants to shoot away from you.

If you haven’t committed, I absolutely don’t recommend using that wheel. They really are made for cruising (on the recent version of the StingRay bike), and I question their strength. A Trials wheel is made for hard punishment, so stick with those for now, and maybe experiment with tires.

Yes, if that wheel is known to be fragile to most people, it is something I would probably break just by looking at it wrong.

As far as using water for training:

The KH is broken, but that is my fault. I damaged the threads on the crank from using the wrong end of the removal tool while half awake and distracted watching Trump saying something stupid on TV.

If you broke a KH you don’t want anything with cotterless cranks.

I am also curious what broke. Depending on what it was we might have tips for better parts or re-enforcing weak points.

The mini fat unicycles are really built as novelties, rather than extra-heavy-duty unicycles. You will want to stick to Trials or MUni style unicycles for now as they are built to take some abuse.

As for innertubes it might be worth while to search for 15 or 16" motorcycle innertubes. 15" is the right size for a trials rim, and 16" for a 20" rim. They are close enough in size that you could interchange them and if running higher pressures would not feel any difference.

EDIT: I just saw this:

Completely understandable. If you did what I think you did all you have to do is run a tap down the threads. If you can’t find a tap locally, the threads are’t too bad, and have a spare crank bolt and a fine cutting wheel, you can cut a slot in the threads of the bolt as a DIY tap. It won’t be able to cut new threads but it could be good enough to clean up the threads in the hub with some elbow grease and cutting oil.

Why were you taking your cranks off?

I changed my mind, this was definitely Trumps fault that my KH is broken. Obviously a Russian connection…

Good to know if I ever have trouble finding proper trials tubes, thanks!

To replace the wheel bearings.

No one had the tap locally, waiting for it to arrive in the mail.

Thanks for the idea on the home made tap, no cutting tool or spare bolt. Much appreciated!

This makes so much more sense as the base for a 20" fat tired uni:

I like that you have the brake option, with or without holes in the rims, etc. Would be nice if in the BTO, seatpost and pedal options were there too, but overall a pretty good variety of choices from the get go.

I did not know Mad4One made a mini-fat. That one is obviously an exception to the built for novelty rather than use generalization I made earlier. I would like to try one one day.

On the subject of your schnuckered threads I just stumbled upon this video that I thought I would share. While I really like those tiny cutting wheels on a dremmel tool he is probably right that a filed grove is better.