[wiredfool]

Some of the lightest road bikes out there are steel, in the ~14lb range.

You can get stupid light in Steel, Ti, Carbon, Aluminum, but once you're in the sub 16ish lb range, you're going to be going with superlight parts all around, as there's just not that much frame left to make light.

You can make a fully equipped (steel) randonneur at 20lbs, with fenders, rack, pump, generator, and lights. It's not cheap (~10k+ is my guess), but man is it a well crafted bike. With some care, I think that style bike can be done with common components and off-the-shelf frames in the 25lb range.

[dfgdghdf]

I'm a big fan of steel bikes, so don't take this the wrong way, but you cannot build a steel bike as light as a carbon one for any reasonable price or robustness. The most high end steel bikes will barely be competitive with mid-level carbon weight-wise. If you are optimizing for weight, carbon is the only way to go. However, there is more to a bike than just weight :)

[wiredfool]

If you're going for stupid light, there are compromises. Money and robustness are the first two things to go.

Rodriguez is advertising production steel bikes at the 14lb level: https://www.rodbikes.com/catalog/outlaw/outlaw-main.html Yeah, they're pricey. (10k) (That's production vs custom frame, meaning that they might have one off the rack in the right measurements, if not it's a couple of hundred to do a custom geo)

But superlight Carbon is going to be up there too, and it's going to use basically the same parts, +- bottom brackets and such. And frankly, I would trust superlight steel before I'd trust superlight carbon.

There are some pretty awesome Ti bikes as well, including custom 3d printed lugs, cranks, forks, stem, etc. They are in the same weight range, and IIRC 8kUKP.

If you're looking at commercial production, probably fair that carbon is going to be lighter. But the the people pushing the edges aren't limited to that.