Need tires.

[jtopiso_imp]

I am afraid, I am entertaining this curious, old-fashioned notion because I was trained this way, and yes, ... I agree with you, it must be called curious lately. Why not scientific ? there is a distinctive difference for me between science and engineering, with repetitive testing of a tire without the aim of further insight into its inner workings I would rather call engineering (product development).

A teacher of mine repeatedly said, partial information is always better than no information. He would however have refused to call fake news and opinions partial information, but would have called (incomplete) statistical information and random samples (here: tires and helmets) very useful.

Now back to the tires, for car tires as I know them better, there are without a doubt:
- significant differences, and prices
- consistent, long-term results showing some brands are better (regardless of marketing)
- that there are trade-offs, and how they work,
- I am not aware (for cars) that a good tire will be a bad performer on the wrong car (as long as we excluded GP etc.).

So can the situation be different, I mean really different for motorcycles. May be this forum can help, may be not. I thought it's worth asking the question. But I am afraid I do not have all the answers and never will

Appreciated your provocative questions, and I am happy that there are less as many rim shapes than head shapes (literally and otherwise).

That happens. Some cars are very sensitive to tyre carcass stiffness (or more prescisely, "cornering stiffness").

Try putting some "uniroyal rainsport" (or any other "soft" tyre) on a rear wheeldrive car, with a weight balance close to 50-50 (bmw 1 series, z3, or an old mazda miata) and you will see how the car behaves completely different compared to the same car running michelin or bridgestone. I'd say most "average drivers" would be able to tell the difference.

Simplifying, "yaw response" comes from the rear axle, and is usually faded by the feedback at the front (most weight is there, and forces go to the driver through the steering wheel). But when the weight at the rear is important (around 50%), tyre stiffness dominates the "response" of the vehicle.

(when feedback is mainly through the steering wheel, driver adpats his style with or without noticing, but when its coming from the rear axle, there is nothing you can do to the steering to anticipate or delay it's response, and if it's the "wrong" -unexpected- response, most drivers feel it).

And if you start mixing tyre brands among axles, then that's another can of worms.