Before I get into this, the Title says road bike. Got it?
There is one simple reason the 1x drive should be a fad on a road bike, and it’s not aesthetics (though it should be).
Where I live and ride, most of the faster crowd rides cassettes that are referred to as “corncobs”. They’re 11/23 tooth, either ten or eleven speed cassettes. The beauty of a corn cob is there’s only one tooth difference from one cog to the next – two for the two biggest cogs on a ten speed and for the biggest cog on an eleven speed. That works out to a change in revolutions per minute of five rpm per gear. They spend most of the time in the big chainring, too, because we have speedbumps for hills in our neck of the woods. Any hill we’ve got can be climbed in the 36/23 combo, the vast majority in the 52/23.
With a 1x drive, corncob cassettes are out of the question except in Florida where only the overpasses can be called “hills”. Actually, I did ride over one bridge in the panhandle that would be near impossible in a big ring, so only southern Florida… The point is, the 1x drive on a road bike is simply too limiting.
Of course, on the other side of that ledger, I’ve got a friend who’s been riding mountain bikes long enough to have thought front fork shocks and disc brakes were fads… so there’s that.
Look at the average enthusiast, though. We don’t even have to use the speedy 24+ mph average group to ixnay the 1x drivetrain. I ride a 52/36 on the Specialized and a 50/34 crank on the Trek below, both with an 11/28 10 speed cassette. I don’t much care about the corncob because I actually travel to places with real hills and I don’t want to be climbing an 18%’er without some gears – and that 36/28 is used regularly when we travel up north or down to Kentucky.
The 1x drive is simply too limiting, especially for group rides, so I’d never buy a road bike that had it. The big problem, the real problem, is in trying to select a gear to match pace with a large, fast group. With the crazy cassettes on a 1x drive, 10 or 11 to 42, you’re jumping three or more teeth for each sprocket – a difference of 15-20 rpm per gear. That’s simply untenable.
A gravel bike would be a different story, though.