Have others encountered this problem (broken bearing casing) so soon after getting a new uni? Am I just unlucky?
Peter Sandstrøm at UDC Sweden will replace your bearings immediately if you send him an e-mail. The customer services there is the best I’ve come across. (Replacing the bearings was on my list :-))
Wow, sorry for my recommendations about tightening spokes, that was definitely the wrong advice, though as any American without access to healthcare will tell you, diagnosing things over the Internet can be tricky. That photo looks bad! Did you (or UDC Sweden) over-tighten the bearing caps?
Anyway, I am pretty sure UDC will send you some new bearings. If you haven’t got a bearing puller, you might ask them to also send you one of those, as you will probably need one.
Well I put it together. I don’t think I over tightened it and have not had troubles with this in the past with my last uni (nor obviously on the right hand side of this one).
That said, now you have me doubting myself so next time I will do it even less, just to be sure!
I doubt this could be caused by overtightening the bearing caps. Looks like a faulty component to me.
Mikefule is probably right. It is also weird that the piece in the photo broke along such straight lines on both sides.
Just in case, though, my method for tightening bearing caps is: holding the long end of the hex key, I turn it until it is just finger tight. If you are the proud owner of a torque wrench, you can undoubtedly give much more exact figures, but basically I just turn the hex key until my fingers don’t want to go any further- firmly, but no biceps or chest muscles, no grunting, no second attempt (unlike when I tighten the crank bolts).
Then I turn the uni upside-down, grab a safe spot on the frame, and give the wheel a good spin. If it goes around about 15 times (give or take 2 or 3) before rolling to a stop, I consider the bearing caps to have the right amount of tightness. This method is based on something I read somewhere on this forum, and, though crude, it seems to work.
I own a torque wrench but would never use it on a bicycle o unicycle.
You can tell how much torque the manufacturer wanted by the size of the nut or bolt they chose to use. If you look at a set of spanners (US = “wrenches”) or Allen keys (US = “hex keys”?) you will see that the handles/levers are longer for the larger sizes. If you put the same amount of effort in with the longer lever, you get proportionally more torque, but the bolt is thicker and can take it.
A bolt should go in easily until it is snug, then you need to apply a bit of torque for the last roughly half a turn. You can do it by feel. If you over-tighten a bolt, it stretches and then twists, then snaps. It only needs to be tight enough to be secure.
Tighten, ride, check, nip tighter if necessary, then check occasionally.
I put the uni together quickly without much thought but I certainly did not “go to town” tightening these as hard as possible. I stopped once it felt secure (no movement if you try and jiggle the the frame relative to the wheel/cranks)
I had already noticed in the past with a previous uni, that if you tighten too much it starts to slow down the wheel … but this wheel was spinning nicely.
Whatever the reason or the failure (bad batch or something I did), I shall be even more cautious in the future.
Are you sure about that? The Allen wrench was patented in 1910 by William G. Allen, whose manufacturing company was located in Hartford, Connecticut (a city now dominated by the insurance industry). I referred to it as a “hex key” because I thought perhaps that name would be more familiar to people outside the US!
I don’t get this spanner business, though. Isn’t a spanner a specific kind of wrench, rather than just any old wrench? And pavement! How do people in Britain know when you are talking about a sidewalk, rather than some other paved surface?
The fact that I am not sure about it was indicated by my use of a question mark in my post. I know the people from many of our former colonies speak and write a variety of arcane dialects and I can’t memorise (with an s) them all. 
Giving alternative US spellings or vocabulary has been a running joke of mine in this forum for many years. Spiffing banter and all that, what?
Over here, traditionally, all open ended or ring ended implements used to undo square or hexagonal headed nuts or bolts are called “spanners”. We even have “adjustable spanners” — and the very best ones have an adjustable head at each end: one end for metric (mm) and the other for Imperial (fractions of an inch).
The only time we use “wrench” traditionally in the context of a tool is a “monkey wrench” (adjustable spanner), a torque wrench, or a plumber’s pipe wrench. Oh, and I think the Torx equivalent of an Allen key has always been called a Torx wrench.
However just as our shops have mysteriously become “stores”, and places that used to repair cars now repair “autos”, our spanners are gradually becoming “wrenches”. No good will come of it, I tell you. Nevertheless, I can forgive much in recognition of the fact that the USA gave the world Hank Williams and Carl Perkins.
Because other paved surfaces have other names!
I know you like to call things by simple names but personally I can’t get on board with fall. Yeah leaves fall off trees, but it’s autumn. 
Yeah, like the verge! When I first encountered that word in Mikefule’s novel, I thought it might be the verge of a nervous breakdown. In the US, it’s called the shoulder, which I suppose is equally confusing.
People say “autumn” in the US too, just not so frequently, -except in New England, of course!
The word “spanner” in the US, if I am not mistaken, is only used to refer to a C-spanner, a tool for removing part of the bottom bracket on a bike. There’s also a channel called C-span on TV, where you can watch Capitalist A debate Capitalist B in Washington DC.
Thanks for the plug. 
I hope you enjoyed it.
Verge: the grassy strip along the edge of a road, especially a minor road. The verge is often the strip of land that separates the road from the hedgerow. Although there is no absolute clarity of definition, a verge would usually be flat enough that a vehicle could park with 2 wheels on it, or even all 4. If it is too steep to do that, it would be a bank.
In the UK, we also have a “hard shoulder” which is a tarmac (or similar) strip as wide as a car and provided for vehicles to stop on when they have broken down.
In Australia, the verge is called the “nature strip” and lies between the “footpath” and the “road”. Between the footpath and the nature strip is the “gutter” where the water flows.
A nature strip covered with “bitumen” would be a “shoulder”.
Well I sent them two emails 6 days back (albeit via the ifx.se kontact address, since that is how they confirmed my order) and never heard a single thing.
I have now tried sending a message via the form on their website, i.e. Kontakta oss på Stockholmkajak
Anyway, since I heard nothing for so long I ordered new bearings and a bearing puller from UDC Denmark (unisalg.dk). UDC Sweden didn’t appear to sell a bearing puller anyway.
So I received the bearing puller and new bearings today. I quickly watched https://www.youtube.com/watch?v=Oy3XvJr61DM and went to work.
However, because the bearing casing is so completely broken, attempting to remove the broken bearings just resulted in the bearing breaking down further, leaving only the inner ring attached. The nimbus bearing puller cannot now fully get a grip on this inner ring. Only the absolute edges can contact the inner ring and attempting to extract is just resulting in damaging the bearing puller (the edged start to bend). So I am now well and truly stuck. I cannot remove the inner ring and I have probably damaged my bearing puller. What now?
if you have a dremel tool, or a small hand held motor tool you can use a cutoff wheel to slot the inner race of the bearing. I would go slowly, and stop before you go through all of the way to protect the spindle. once you get a slot into the race you should be able use a cold chisel, or maybe even a straght screwdriver to break it open, and then it should be easy to pull off. If it is still difficult you may need to make a second slot.
I don’t but I have a friend who would (currently on holiday). I shall update when i have tried this.
Just an update. Peter replied. I think I might have caused some confusion because of the fact that I used a different email address than the one I ordered from.
Anyway he (and hence UDC Sweden) have been very helpful and indeed offered to send replacement parts immediately. I felt I should mention this so that others are aware that indeed the service is good.
Nonetheless I have told them that since I have a new set of bearings now they need not bother.
Super neat!