Anyone else notice their road bike's rear tire wearing flat in the center while their front tire maintains a nice round radius? Time to rotate?

Yep... well documented, rear tire wears faster than front.

Lots of theories about tire rotation. Most people suggest keeping the BEST tire on front. But, if the rear is in good shape, then there is no reason not to move it forward.

Another option is to wear out the rear, then move the front back, and put a new tire on the front.

Tire rotation is easier if you setup your bike like this:
https://www.bikeforums.net/19727469-post14829.html

Lots of riders do but I don't.

I run my back tire until I can see a circumferential casing line all the way around the center. Then I throw it away and buy a new tire.

Now the question becomes: "Should I put the new tire on the front or back?"
I think that most riders will say to put the new, presumably better tire on the front and rotate the used one to the back. The contrary theory holds that many tire issues appear in for first few hundred miles of use so it's better to keep the "proven performer" on the front.

Yep, my last blowout was 75 miles from new with the tire

Another reason not to rotate is if one chooses to mount say 25mm tires on the rear, and 23mm tires on the front.

My last Grand Prix 4-Seasons tire wore down quickly. If I ever choose to ride those again, they'll spend most of their time on the front, and the rear will get a longer wearing Gator Hardshell or similar tire.

It happens because you only apply drive force to the rear tire, and that when the bike is mostly upright, so the rubber in the center scuffs against the ground. Plus, a lot of people preferentially use their rear brake, skidding it when coming to a fast stop.

In contrast, the front tire almost never scuffs the ground.

More weight on the rear, force from the drive train, skidding if you do that. Maybe even the higher inflation we usually use on the rear also contributes.

I think (not 100% certain on this part) that the constant little turns we do on the front to keep balance moves the contact patch from side to side and evens out the wear some, as opposed to right down the center.

I wouldn't rotate the more worn tire to the front, especially if it was squared off.

The bike won't handle the same with a front tire that is worn flat in the center (yes, I've tried it). I would not recommend rotating your tires. I usually replace both tires (I use the same size front and back) and save the old front tire. When the new rear wears, I replace it with the old front one I had saved. And then I just repeat the process.

I don't think I can tell the difference, but I'm not doing hairpin curves at 50 MPH either.

I replace the rear tire and leave front alone. Then when the back needs replacing again I replace the front also.

Seems the consensus here is to not put the back tire on front. Good, I was hesitant to even consider that as it has a bit of "corners" on it due to the flat center and that would seem very unstable to me in a turn. I live in mountainous country and some downhills require pretty good handling. Corners on a front tire don't seem conducive to that! lol
So I guess I will leave the front intact and just order a rear replacement. They are Continental Super Sports.
Thanks for the replies.

Many mountain bikes now run different front/rear tires. The front gets an aggressive tread designed for cornering, while the rear gets a tire designed to put power down and better rolling, since it has more weight.

Or you could do my current bike, which has 25mm front, 23mm rear. This is because I wanted to try 25mm tires, but wanted to move the old tire to the back, so there you go. FWIW I'm going back to 23mm.

This. I usually get 1 front to 2, to even, 3 rears.

Move front tire to back and install new tire on front.

Rear tire wears out, rinse and repeat.

Both of my tires wear a flat across the surface.

+1) If anything, put a brand new tire on the front, then the current front on the rear.. the failure of a front tire is to be avoided.