I post this only as a caveat - and because I have considerable experience with this issue:
If you have an accident while running a car tire on a motorcycle, you will have a GREAT DEAL of trouble obtaining compensation for your injuries (if you are a plaintiff) or defending a claim for injuries brought against you (if you are a defendant). Expert testimony will establish that the vehicular dynamics of operating a motorcycle with a car tire as the driving wheel, is inherently dangerous, outside of the contemplation of virtually EVERY design engineer who designs motorcycles and outside the contemplation of EVERY designer who designs either
motorcycle tires or car tires. You will not be able to find a tire industry engineer who will testify under oath that a car tire has the necessary directional stability and cornering characteristics to be SAFELY and PREDICTABLY used on a motorcycle under all operating conditions. They will, however, testify that both the profile and carcass design of a car tire are inherently antithetical to the physical environment and physical forces within which a motorcycle operates. The fact that you were operating a motorcycle with a car tire installed WILL become a central issue in your litigation - and it will not be to your benefit.
Take this for what it's worth, but I can tell you that in 40 years of legal practice - I have NEVER lost a motorcycle case I've tried to a jury, either for a plaintiff of a defendant.
*************************************************
STANDARD OBLIGATORY DISCLAIMER:
The above does not constitute legal advice. It is posted for general informational purposes only. No attorney-client relationship is formed by the posting of this material and you have no right to rely on it. I am probably not licensed to practice as an attorney in the jurisdiction where you reside. If these issues affect you - you should seek competent legal counsel in the jurisdiction where you reside. The law varies from jurisdiction to jurisdiction and what is stated here may or may not constitute the law in your jurisdiction.
So there!