Tire stiffness PER SIDE of tire 1

[KevinK2]

Tire stiffnes is a well described subject. For zero camber, a simple 2D model of the tire could be represented by 2 side-springs, one at each side of the wheel. However, I recently went from a 17" set to a 16" set, and found that, when subjected to a non-symetric load condition, ther was a surprising large effect on the "side-spring" rate .... much softer.

The test was my driveway's slightly uphill entry. There is a concave drain gutter along the road I have to cross to enter the driveway at about a 45 deg turn-in angle to the road. The tires cross this effective bump one tire side at a time. I think the big improvement in compliance is due to each sidewall distorting in a non traditional way, acting as a much "softer" side spring for the 16" set, vs the 17" set (same OD).

Any data or comments on this effect?

Kevin

 

[KevinK2]

If a stiff sidewall makes your day, had you ever considered a runflat? Then you can eliminate the spare, the jack, and the tools, too...

What thread are you reading?

.

 

[NormPeterson]

Your "garage Instron" experiment might work better if you can come up with a way for the final orientation of the body/chassis to be essentially the same as it is when all four wheels are loaded and sitting on level ground. Otherwise you'll shift weight by virtue of vertical CG height and inclination.


I hope that it can be assumed that the person having trouble avoiding curbs is NOT the same person who knows what DOT R-compound tires are.


Norm

 

[KevinK2]

I could use support blocks, equally at RF and LR tires, until the RR looses contact.

I hope that it can be assumed that the person having trouble avoiding curbs is NOT the same person who knows what DOT R-compound tires are.

I hope so too ....