it would help us a lot, IF, we knew what bike you are talking about ???
EDIT: when I exited this post, I then saw that you made an Intro post also and caught that info.
I placed that in your Signature for future clarifications:
2003 Goldwing 1800
the folks who write manuals are rarely Mechanically Inclined, sorry to say.
I currently have a Dunlop E4 on the rear of my bike in the proper size.
I also have a Car Tire mounted on a spare rim, that is a ZP RF winter tread.
I purposely chose a slightly smaller diameter tire this time, with a more rounded edges on the profile then the first CT that I used, which was a Michelin Primacy Alpin.... I did not like that tire because it tries to stand up in turns at slow speeds..... and here where I live, the speed limits are 25 mph...