As the title implies, is this a PW bottom bracket? Doesn't come with cups, and the bearings seem to be a bit more inboard than I recall. Any replies would be greatly appreciated.

at a glance: probably, but if the seals on the bearings are brick red, then it's a 90+% . I can't discern a color in this shot. Slight chance it could be a Sun Tour unit since those also had a "smooth" shell like that.

no, it is not a Phil. I think it is a shimano knock off with the threaded collars removed

if there are no cups, how does it mount in the frame ? one wonders

/markp

On a Phil the shoulders of the bearings are visibly different diameter from the sleeve connecting them. This isn"t a Phil Wood.

No expert, so a few pics of an early one that came on a 1974 bicycle I bought last fall.

That is a version I have not seen yet.
I am familiar with the version [MENTION=1977]Feldman[/MENTION] describes and two much more recent versions, both of those having the bearings within the outer case, flush to the ends. The most recent with a necked down area near the center, not sure the how of that assembly for service.

Phil is and was a flexible producer, designs changed.

^that^ (from sd5782) is the early circa 1970s era Phil I thought we were seeing in the OP's pic, in which the cart bearings are pressed flush into the center barrel but...cannot be 100% certain without more views.
Here's a couple more courtesy of Velobase



and there were a few Shimano units with BOTH cups removable but the ones I am most familiar (like this UN-72) have a center section with pronounced "step" in diameter like this:


BTW Phil calls their threaded mounting elements "rings" not "cups", sold in at least 3 threadings (Brit/ISO, FR and Ital) but at one time they included Swiss and might have also sold Raleigh-specific 26tpi?
Some ring pairs were steel-only but a couple (maybe Brit and Ital) could also be had in AL-alloy

unworthy1 that Phil BB you show is a very early one. That version had a spindle welded in the middle. they failed.

had not seen one of those for years.

Based on your pic, I will allow that the OP's unit MAY be a phil unit, also looking at the machining on the spindle flats.

but again, I would not ride one of those.

/markp

One of the <10% with non red bearings (black).

Interesting comment by [MENTION=167931]mpetry912[/MENTION] on the welded spindle. I knew it was hollow, so I took a look. One could see an increased inner diameter in the center section of the spindle. The outside ends were the same inner diameter of the fixing bolts. One couldn’t see the inside diameter of the center section, but it was fatter for sure. It obviously had to be put together in pieces as mentioned.

Ok, upon further inspection, it is a Phil Wood BB. Red seals, with USA on the seals in tiny lettering. Plus additional image searching revealed some older models with the bearings completely flush with the shell. Thanks to everyone for the replies. More concerning to me is the story of a failed spindle. mpetry912 , was this from personal experience, or an anecdote that you heard? I would rather not end up like Laurent Fignon.

My own personal experience: I have run a handful of Phil Wood BB units in different bikes over the years, including several that were this "very early" variety.
I never had any spindle fail in any Phil BB.
Possible that every one of my old vintage BBs had been serviced by Phil in San Jose and could be they replaced the spindles with un-welded units...but I don't know.
I'm 99% sure I have at least one, maybe two, of this era BB installed and in use in current riders.
If I'm sitting on a "time bomb" I have no idea, but given the performance I know I've had I'm not concerned

I've ridden phil hubs and BBs for my whole cycling career, have them on many of my past and present bikes.

never had a single problem with any of them. However I never rode one of these very early ones. I have heard of several failing.

I would not ride it, but that's just me. You do you.

/markp

FYI, Boulder Bicycle has a sale on of various threaded Phil Wood BB retaining cups.

https://boulderbicycle.bike/bottom-b...vintage-other/