On 28/06/2018 09:46, The Natural Philosopher wrote:
On 27/06/18 19:36, Tim Streater wrote:
You can also imagine that if you could get hold of a tire of the same
overall diameter but to go on a much smaller wheel, that the spiralling
effect when flat would be much more pronounced as the tire wall would
be bigger. But, once spiralled up, one turn

I've been thinking about this a lot trying to make it simple enough for
even a remoaner to understand.

The fallacy is in Huge's basic premise that because the axle is a given
height above te ground, that represents the 'effective/rolling radius*'
of the tyre.

It does not.

The 'effective/rolling radius' is /always/ the circumference divided by
2 PI.

Rubbish.

The tread on the tyre and the side walls deform as the tyre rotates
changing the actual circumference.
The change depends on the contact length which changes with pressure,
load, tread pattern, rubber compound, type of belts, etc.

Even a steel tyre like those on trains deforms as it rotates.