200 miles on 17's...some things to keep in mind...

[themess]

I don't question the importance of slip angle, which is the topic of your first reference. I do question the other assumptions, mostly about tire stiffness. Radial and bias ply tire sidewall stiffness can be very similar. While the center of a radial tire sidewall is usually less stiff than that of a bias ply tire, the bead package of a radial tire is usually stiffened more, and the upper sidewall is also usually stiffer, to protect the edges of the tread and to keep the tread flatter.

It seems to me that wider tires change the contact patch enough that the slight difference in stiffness may no longer be relevant.

I'll look at the second reference, since it specifically addresses tire stiffness.

I've usually seen the better handling of radial tires attributed to maintaining a flatter tread contact patch, with less squirm.

[themess]

The motorcycle dynamics book diagrams show the front tire turning in the same direction as the turn, instead of countersteering!

[posplayr]

themess

A 180/55-17 tire on a 5.5" rim is not going to have much side wall flex, so there is not much danger in mixing this with a bias ply tire.

I'm pretty sure that was the qualification of the rear radial tire warning statement; i.e. it is a tall radial.

Pos

[76FJ55]

Of course the front tire is turned into the turn. The whole counter steering issue is widely miss under stood and an unknow concept to some. The counter steer is merely used to initiate the turn, then the front wheel is turned into the corner. Basically it works like this. Initially you are riding along ballanced, you now want to make a right turn. you willinitially turn the bars/wheel slightly left this upsets the balance of the motorcycle by causing the contact path to move to the left as the bike moves forward. now with the contact patch left of the cg the bike will start to fall right. you now transition from counter steer to turning into the corner. this is done to balance the force of gravity wnting to make the bike fall over with the centripetal acceleration force generated by the tires driving the bike into the corner. when held at static equalibrium you will maintain a continuous rate of turn. now when you have reached your new desired heading you will again upset the equalibrium by turning the bars/wheel into the corner further than required to maintain the arc you are traveling. this will cause a greater amount of cornering force than can ge counteracted by gravity causing the bike to move back towards the upright position....
Actually this is a continuous unconsious action being performed to balance and control direction. this is ofcourse aided by the geometry of the bike which in a sense acan be self stabilizing (usually mostly effected by trail), but these movements must be made in order to control direction.

[pkbjamn]

I've often tried to explain this phenomenon to non-riders (and riders alike!) using much of the terminology in your response, but not all of it. This very much helps to qualify the explanation of counter-steering. Thank you for increasing my knowledge and ability to propagate it.