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[BMW0]

The plus side of RFTs are that they are stiff and give the driver predictable input from even the slight amount of steering input. Almost sounds like RFTs should be used on the track. I like the look and handling of the RFTs offer and ofcourse the safety of highspeed stability after a puncture and or penetration of a foreign object. The demerits are: the high price, ride comfort, heavy weight, and very hard to obtain even if you have the money to buy them. Overall, its a work in progress. Eventually RFTs might be able to overcome most of the adverse effects it has spawned ever since their introduction.

[sdiver68]

Originally Posted by boyce'06 330i

Correct. In a race tire you want compliance, grip, steering response and predictability at the edge of traction. These are not qualities of a stiff sidewall.

The suspensions in race cars (F1) are so stiff to reduce body roll, squat and diving, that a stiff sidewalled tire would make the car unpredictable over the slightest of bumps. A scary thought at 190 mph!

You hit the nail on the head in your 2nd paragraph.

You note the other suspension characteristics of an F1 car make a certain sidewall stiffness optimal. I'll note that the 335 suspension was tuned by BMW engineers for the stiffness of RFT's.