They should have designed them with a decent seal. It could be cup and cone though, I'll check if you mentioned the hub brand. But getting oil in is unlikely.
My bearings went, and were supposedly serviced, but ended up worse and the wheel got retired.
As has been said, if you leave it too long the points of contact get deformed and you can't usually change the cones, or what have you.
Mine became tougher to ride and noisier, but in my case more consistently noisy during the rotation.
Do you have a lbs? Or are you enjoying the detective work too much?
At some point I really started to dislike lbs's.
OFFTOPIC>
Too much serious flaws in their work. The list is endless. Some examples:
- Ball too much in bearing, cup and conus pushed away from eachother, wheel wobbling like crazy. A serviced wheel, stored as a spare, so a second misery on top of a first.
- Bike size too small despite having mentioned importance of frame size (2 new bikes)
- Stem mounted not deep enough, causing steering to get dismounted in the middle of riding, with me uncontrolled between 2 cars having to use a hedge to achieve a stop. Humor, but just think about it...
- A spacer to achieve straight chainline being a reused part of aluminium with 3 holes drilled in it. I left the lbs and the first push on the pedal broke it.
- A new bike (latest) asked for and designed as durable, but delivered with a 5 mm wrong chainline despite dealer having said during the built to order phase that the chainline wasn't 100% straight but that they found a solution. They didn't, but kept mouth shut about it, even when I asked why my chain hung tilted like a V, to only finally admit after I asked on a forum how to measure it myself and did so, and after a first reaction that on internet there is alot said but little of it is true.
- Same new bike (4300 euro), hydraulic brake oil line rear mounted with a too short corner causing it to break after time
- Again same, asked for 1/8" drivetrain, but mounted a 3/32" chainring without saying. I discovered it when it wore to shark fins in a single month.
- Again same, one month riding, wobbling bottom bracket axle, chainring scratching the frame, loosened by itself, dealer hadn't applied Loctite despite web advertisements stating "Loctite by standard". And his first diagnosis was bearings broke down. And he even said due to the 3 weeks wait for bearings replacement service that I safely could further use the bike till then, while the chainring was already scratching the frame!
- Bike stand mounted with A2 (grade 304) stainless steel bolts through aluminium. Galvanic corrosion fret it out so worse that the mount loosened every 3 usages and retensionings.
- Rim tape too narrow, causing inner tire to contact metal of rim and being damaged, discovered it when I suffered a flat without apparent reason. The tape width was the same as the rim but the rim basis is curved so longer, too stupid to realize or just not interested enough to do a job well?
- When asking, dealer told me that I wouldn't have to deflate the tire to take out the wheel, he even said that that would be ridiculous. It was like that - the Magura hydraulic brakes pads mounts were too close to eachother to allow a blown up tire to pass.
- I had asked a certain gear ratio but he recommended (as turnt out later the frame clearance was too limited to allow a bigger chainring) another ratio, but it was an integer, causing the chains wear to be concentrated and a huge tension variation.
- The 6 bolts of the rear cog had just a couple threads, they were 4 mm shorter than required length in specifications. And the dealer applied red Loctite, causing thread damage when removed - I had to tap the holes.
And so on...
I'm using bikes for everything (no car) since 20 years and over that time I had (and left) 5 dealers, due to bad work inflicting me misery. Some day it became too much and I moved to singlespeed then fixed gear and since I did most of the work myself, instead of having to wait 3 weeks then 3 months and finally 9 months to get a bike serviced, with my other bike already needing it too.
ONTOPIC>
So I'm not enjoying detective work, I try to learn things enough to cope with them myself. That's independency, freedom, and reliability.
The hub is "Surly hub Ultra singlespeed disc 135x10mm 36G" but the "New" of the current isn't mentioned anywhere.
The tech specs of the New are here:
https://surlybikes.com/uploads/downloads/Surly_UltraNew_Hub_Axle_Kit_Instructions.pdf
But bearings seem still unlikely to me as cause of the noise. I had a flat two days ago and the noise started after replacing the inner tube and the deflation>reinflation of the process.
Also nothing happened that day explaining a sudden reappearance of the noise.
A nail punctured outer and inner tire, that was it. A clean round small hole, straight on the tire. The nail was like new, not bent, nothing. So I doubt the outer tires carcas could have been damaged in such a way that it deforms enough to bridge the large clearance to hit something of the frame.