On 28/06/2018 21:43, Jeff wrote:


"T i m" wrote in message
...

Bingo.

I was walking round the park with our daughter earlier and I gave her
the nutshell iTPMS overview and asked her how she thought it might
work ... how the circumference could become shorter for the iTPMS to
'sense' the increased RPM.

"As the tyre gets flatter it spreads more and that makes the
circumference shorter and so the revs higher?"

Not convinced and that summary makes no sense either. Why would
the tyre 'spread more' as it gets flatter and why would the circumference
get shorter even if it did

Well that is the obvious bit, less pressure means more of the tyre has
to be in contact with the road to take the load.

The circumference of a tyre is not a fixed length.
Its flexible blocks (the tread) mounted on a flexible base mounted on a
flexible core of wires/nylon (the plys).

As the tyre hits the road the blocks get closer together so the
circumference decreases.

Even slicks compress because they usually use a soft rubber.

Shame TNP is so fixed he can't understand that this is too complex for
his closed mind.