Caramel Sundae (The dogs)
A number of riders have found the benefits of using a car tire on the rear of a Goldwing. The practice was early referred to as "being on the Darkside" since people though we would all die a flaming death. I was the first or second person to try it on a Goldwing and certainly the first to document it. At one point, I have some reviews and information. However, a forum space was created for the discussion and now includes much more information than what I had. The forum can be found at:
I also have to give a link to this site which is where I first got information:
I will give you some basics here. First, it's about safety. Car tires (CT or sometimes bad-ass motorcycle tire (BMT)) have a much larger contact area so problems with the road get distributed. Traction is massively improved, bridge grates are irrelevant, and gravel is much less of an issue. Second, the sidewalls flex so more road problems are absorbed. About 75% of the jarring goes away. Your passengers will love it. Third, the same flex of the sidewall lets it spread out in corners. The harder you corner, the more it spreads out and puts rubber on the ground. You will hang the 'Wing up on the engine guards before you roll the tire all the way onto its sidewalls. Fourth, the tire is much stronger - especially run-flat tires. If you have a sudden loss of air, a CT will provide some time to recover. (One run-flat I used rode so well without air, I didn't know it was flat.) If you do pick up a nail, a CT can take a patch much better; and if you smash into a pot-hole or something, the rear tire will absorb the impact instead of throwing the bike around. Fifth that comes to mind (some guys find ten) is the long life of a CT. I get about 20 - 25 thousand miles out of mine. Some guys burn softer tires faster but they were burning up motorcycle tires (MT) in as littel as 5,000 miles. Naysayers (people who dis-believe the value of a CT) say Darksiders are sacrificing safety to save money on tires. As I have noted, the safety issues are first.
All these benefits do have a couple of draw-backs. Because the tire is wider and flat, it takes a little more pressure to start a turn and you have to hold the handlebars throughout the turn. With a MT, you can start the corner and pretty much let go of the handlebars. However, with a CT you only have to release the pressure to come out of the turn. The sidewalls will unflex and help you. Also, if only one side of the tire is supported such as being in a rut or on a bump, the bike will want to tip to the unsupported side. This will introduce some steering input. At speed it is easy to countersteer to correct it, but at a stop such as an intersection, the bike gets kind of heavy.
Tire sizes range from 175/60/16 to 205/50/16 with the 195's being the most popular. A number of 195's exist but they usually need to be ordered. I used a Dunlop Wintersport 3D 175/60/16 RF and loved it. The steering issues are nearly non-existent and the tire had excellent traction and handling. However, it took 9 months to get it. I now have a Federal 175/60/16 non-RF and still like it a lot. I also had good luck with a Goodyear Ultragrip 195/55/16. I like the traction of snow tires in the rain. About every tire available has been discussed in the forum I linked to earlier. 205's are nice to know about because they are easy to find. However, anything over a 205/50 may rub your fender wells.
The 2018 Goldwing uses 200/55/16 tires so a whole slew of 205/x/16s are available for testing. Should be fun!
We have also found that bias ply tires work very well up front. Many guys use a rear tire although I prefer the Dunlop E3 bias. It wears very evenly, is strong enough to run flat, and lasts about 20K without affecting the handling through its life.
Feel free to contact me if you have any questions. It is safe. It is proven. If you don't like it, you'll only by out a couple hundred bucks and you can probably sell the tire to get some of your money back. I'd say about 1% of Darksiders go back (but then some come back). It's really not hard to make the transition.
Enjoy your ride!