I picked up an old Otero bike awhile back that came with these Araya rims. I haven't found much about them so I'm checking here to see what y'all can tell me. They are not magnetic, no hook, single wall.I have seen that the w/o on the label means 'wired on'. Does that just mean the tires should have a wire bead?

"Wired/on High Pressure"
I still have one of these on the rear of the UO-8. I use a 27 x 1-1/4" tire, inflated to about 80 PSI, without issue.

Near copy of a Weinmann rim way back.
not light but not steel heavy either
(excluding Dunlop special lightweight rims)

I've got a couple of sets of those Araya rims, and I run wire bead tires. There are various mentions of guys running folding tires at lower pressures on this forum. It's not much fun blowing a tire off of a rim, and it could be a safety issue.

Otero or Orero?

Otero
https://www.thebeautifulbicycle.com/...est-bike-shop/

Yes.

Panaracer Paselas can be had so, and they are a proper cycle tyre, not one of those horrible 30tpi things.

Today I mounted the CST C-979D, 1-3/8" (37-630) tires I bought direct from China on those very rims.
It was a little tough getting them on (and centering the valve stem) because they were stiff and also quite grippy against the rim, being that they were new and clean.

The tires measure a full 35mm wide an hour after mounting with 75psi (will be lowering to 50psi for tonight's ride).

I've used these same Araya (and similar Ukai) rims on many bikes over the years, never had a problem with the alloy being soft and that's a good thing.
Their outside width is 25mm and I believe their inside width is 18mm.

I did once run folding-bead, 1-3/8" Michelin Hi-Lite Tour tires on these same rims. I was able to use 70psi but no more, lest the bead started climbing upward at some random position on the rim. It was safe long-term at 55psi though.

These rims weigh about 550g and the lightest steel rims are about 750g. They can be found in 36- and 40-hole in 27" size.

These were considered good rims back in the early '80's. I must have a bike with them. I hope I do. All tires in my fleet are wire bead, so no issues with hookless rims or even trying to remember which bikes have which configuration rim.

@dddd thanks for the info on that CST C-979D, 27 " x 1-3/8" tires.

@Chuckybb are you planning on building wheels with these rims?

I'm just investigating the rims for now. I had hoped to find out the year of manufacture.

Peak production may have been early-to-mid 70's, after which a narrower version became popular with lighter 1-1/8" tires fitted by OEM's like Fuji and all the others.
Those 1-1/8" tires could be as narrow as 24mm fitted on the newer (only about 15-16mm internal width, ~22mm outside width).

There were at least two versions (subtle shaping differences) of the 25mm wide Araya singlewall alloy rims.

I took my first ride on the 35mm-wide 1-3/8" CST C-979D tires last night, at a moderate 55psi for my 140lb heft. They aren't a fast tire compared to the (actual) 30mm-wide old tires I had fitted to my Miyata Six-Ten. The weight increase is obvious but does also slow the steering in what I thought was a good way, given that the Six-Ten has relatively "sprightly" 73-degree angles for a touring bike.

I can't wait to try these AliExpress-sourced tires off road!
They currently list at only $11 each, with free shipping, which is very economical for such a tire from a quality brand like CST (now $3 less than when I bought them).
By comparison, the more age-stretched 1-3/8" Kenda Cross-Cyclo rear tire that I was replacing measured only 30mm, and I bought these CST's because they are the (actually) widest 27" tire available (though not stocked by anyone in the US, and apparently never have been).
SHOWN BELOW ONLY TEST-FITTED LAST YEAR TO A DIFFERENT, ONLY SLIGHTLY-NARROWER DOUBLE-WALLED 27" RIM, BRIGHT PRINTED LABEL HAVING BOLD MANDARIN TEST:

[QUOTE=chuckybb;23389989]I picked up an old Otero bike awhile back that came with these Araya rims. I haven't found much about them so I'm checking here to see what y'all can tell me. They are not magnetic, no hook, single wall.I have seen that the w/o on the label means 'wired on'. Does that just mean the tires should have a wire bead?

I have those rims on my 1972 Concord Deluxe. (I think its a 72, serial # has no year, only 5 digits but have had it since new) Also bought a 1975 parts bike that has them. I used to run wired rim tires with 100psi in them with no problems. But read about them coming off so I usually run 80psi now.
I also have a set of Araya rims bellow that have the W/O but are hooked rims???? Those came off an old Miyata Nimbus.