Originally Posted by not2fast
I have to ask....why would you do it? A car tire is meant to have the tread in full contact with the road surface. A motorcycle tire is contoured (rounded) for a reason. It can grip when the bike is leaning into a turn. Car tires and not designed to be run on the sidewall and will attempt to cancel the lean angle. This should be obvious if you ever ran your rear tire down to where it has no center tread left.
If you have a trike or sidecar then the car tire might work, otherwise the lack of safety using the car tire would be too risky for me.
I'll bite on this one:
the car tire works perfectly fine on a motorcycle, I noticed a slight difference in handling when I first put a car tire on but after about 2 corners you don't even notice it, it's cheaper to start with, will outlast a motorcycle tire by a factor of 3 to 4 or better, gives excellent grip in the rain and is generally a better engineered contact point between the bike and the road than a motorcycle tire!
but then YMMV