Here are some pics of front and rear tire -- all are high mileage hard rubber tires.

Read "Thinkn' & Drinkin'" thread (page 3-4) for full description of exactly how a car tire feels when you are first getting used to it (retraining your hind brain that controls your sensation of balance and other involuntary functions).

Some who have done this car tire trick claim to have adjusted easily within a mile or so to how a car tire feels, hey, it took me a week and a half to get completely acclimated.  Once this takes place, the tire feels normal to you.

(it takes over a month for the car tire to "break in" anyway -- they are drastically more durable in the rubber department)

Heck, it took me two days to stop getting "weird" sensations from the new front tire I just mounted -- I was riding "too fast" and rolling "too deep into turns" according to my hind brain.  I guess I am just sensitive to that sort of stuff.  (my foot pegs agreed with my hind brain BTW -- new tire likes fast sweeper turns a lot more than a stock IRC front tire did).

Bill, that rear tire has been on there almost a full IRC rear tire's total life span worth of miles now and I rode it hard the whole time.  At least the nubbies are off of it now, they lasted a month or more before they wore off.  

I might as well decide I like the tire, it is going to be with me for several years yet.