Some run the 140/75/r17 on the front but they do not make a 240 16 inch rear. Now buy a 18 inch rim and you'll be able to run a full set. Your best bet for the rear is a bridgestone exedra max 240/55/r16 and either the 140 Michelin or say a 140 cobra on the front.
Spawn, Roadsters have the same wheels as the Classic, so lots of Captains should be able to give their comments on the front Commander II.
I have run the first Exedra combination suggested by warp9.9.
Today I removed a worn-out Commander II 140/75 front, which I used with a 240/55 Exedra Max rear. Grip and steering with the Commander were very good, but it wore down to 1mm tread in 8,000 miles.
The OEM Metzeler 150/80 front lasted 11,000 miles, with some tread left. I ran it at 38psi.
Rapid wear of the Commander II went against everything I'd read. I might have had a bad one, but it might be due to the greater countersteering effort needed by the Exedra max, compared with the 240 Metz. I ran it at 40psi, all miles solo, no trailer.
Today I fitted a 140/75 Avon AV71 Cobra front. Waiting for the freeze to end so I can ride.
Off-topic comments on rear tires:
I had no probems with the OEM Metzeler. It howled in corners, becoming louder as it became more squared off, but the steering remained OK throughout its 11,000 mile life. I had no issues with grip.
Next was the 240/55 Exedra, which I initially used with the OEM Metz front, then the Commander. From the beginning, the Exedra needed more counter steering effort than the Metz rear. I removed the Exedra after 8,000 miles because it had squared off so much that steering had become high effort. It had at least 2,000 miles of tread remaining but it picked up a nail. I used a rubber plug for a while, but wasn't confident it would hold. Removing the tire to fit a proper glued plug/patch wasn't worth it. I was ready for a new tire by then.
I haven't read any comments on the reluctance of the 240/55 Exedra to roll on its side, so maybe I got a bad one? I ran it at 40psi, all miles solo.
I recently fitted a 200/60 Exedra Max on the rear, haven't covered many miles yet, but I really like the effortless steering. This tire is much too small for the rim, the sidewalls are NOT in the position designed by Bridgestone, and I'm NOT suggesting anyone else try it. This is an experiment I'm conducting, out of curiosity. I wish Triumph had used this size as OEM, with the appropriate rim (6"). The bike still looks tough with the 200 tire.
As you can tell by the mileage I get from tires, I ride conservatively most of the time. But I enjoy corners, I sometimes ground footpeg feelers, and my chicken strips are narrower than most. YMMV.