I had about 100K miles combined on the Darkside of a Roadstar and a Venture (Yamaha) It was fantastic to say the least. Doing it right you match it with a Rear tire for the front that leans in unison with the Wider Rear you installed. You get your Air pressures dialed in and off you go and change the both of the tires out at around 30K miles (They will go more in my cases but they just feel different that last 1/4 of life)
With all that experience I say DO NOT put one on a Connie. I would LOVE to if there was a combo and a need.
First, It's a Cruiser thing. They are not getting the lean angle we do and the main reason is longivity for a trip. I was laid off at the time I did it and rode over 35K two years in a row. I was sick of changing tires on the road. AND my bike two up loaded was over the Gross Weight rating of any MC tire available so right there it was safer.
It also raised the bike a bit giving me more clearance to lean more and I did, scraping the exhaust.
On a Road bike, it is an advantage, You are just touring, riding, long, just one loop of the USA and you would change tires twice, With the Darkside you can loop the USA twice and not change tires. Traction was crazy good, Mud, snow, sleet, hail, sand, gravel and in the rain it shot back a Rooster tail! The beefier Rear on the front really felt good too in the combo.
Here was the problem. Typically The Darkside choice is a Race or Taxi type tire. I had a taxi tire on one bike and a Front Dragster tire on the Other. They had incredibly strong sidewalls to handle the force all the naysayers **** their panties over. Trust me that was never an issue. But here is what is an issue. Of course it's a Radial tire, and it does flex, so will your butthole the first time you are leaning into curvy ramp and also hit some bumps at the same time. Leaned, the bike bounces, like a ball. It's an uneasy feeling that will upset you if you don't keep your nerve and ride it out.
I should mention this same flex the radial tires have when going over bumps adds an incredible amount of comfort in it's shock absorbing capabilities, another Darkside cruiser advantage, Ride comfort!
Another thing is Speed, Cruisers are not getting to, or Over 100 MPH as fast as we do. And there is the other weakness of the Darkside tire, if you spin it too quickly it can't change it's shape as fast as it needs to and you will get what those that have soiled their panties call Tank Slap. They don't know what it was.
The Car tire can go over 100 in my cases easily. UNTIL you add a curve to the process and it is there the tire can't handle the transition from it's design to run flat, to run on the edge at high speed. It will fight you and it will win if you don't back it down.
So thats what makes it a SERIOUS NO GO for a C14 or really any Sport bike.
You can mount one on a Cruiser and go all 30K miles floating around sight seeing even aggressively slaying the dragon. It's at High speed where the tire edge cannot change quick enough to keep up with the speed, once the tire deforms, it will buck you. I had mine up to 110 on a straight, I also nearly lost it in an Interstate curve going 90.
A Connie is always quickly accelerating, and going fast into curves. (At least I am) Even if you could (And I know of two that have) Fit a tire to the rim and run it. You would be limiting the bike to cruiser ability.
The first time you hit bumps or holes in a curve you might get a lesson your road rash would prove you got.
If you were over 100 and hit a curve, you might just totally lose it altogether! Like I said, the tire can flex up to normal speeds, but beyond that, once it transfers the weight onto that stronger sidewall Darksiders Hand pick, The whole handling of the bike changes and the tire, suspension and the ride can't keep up with those changes and there is the opportunity for the catastrophic results Darksiders warn about.
Yes, I could mount A rear Darkside and ride the US knowing all this, but I have just crippled the agility and speed of a great bike. I'd get 30K miles but I would not have much fun in the curves doing it. And high speeds would be iffy.
So although I would LOVE to. I have to be thankful for the Traction Control I have and the ABS (Two things my Darkside Bikes did not have and the Darkside configuration Really helped with, Traction going and stopping!)
The only drawback we have is, changing, at least, the rear tire on a 10K mile plus trip at least once and Both tires before 22K PITA yes, but small price to pay for all the leaning and high speeds you get to do.
I did keep my Darkside bike for one winter, because I always rode all winter long on the darkside. But I let it go because the Connie was so much more fun to ride and the maint of two bikes was not in my lifestyle.
So, with the fact that the rear tires can't really handle sport bike speeds and lean angles, and that I doubt a Rear MC tire on the front could ever be a possibility on a Connie due to the cramped wheel well. I say we will NEVER see the Darkside properly and safely run on a C14.
If you want that, buy a bike that is popular in the Darkside tire database. I've seen one Concours Darkside listed (NO REAR TIRE ON THE FRONT so it is an Incomplete Darkside IMHO.) and I doubt he really liked it. IF he's still alive, the tire he mounted has been known to shred on cars.
If I ever get a GW, I will go back to the darkside if they don't make it illegal, but as much as a LOVED the darkside on my Cruisers, there is no way I see me running it on a Connie as much as i would love to go 30K again without changing tires.