On (01 Nov 98) Theo Bee wrote to Roy McNeill...

 TB> Going against established wisdom and it "is so simple stupid"
 TB> arguements is paramount to uphill battles and windmill fighting.

It feels more like trying to stop a bulldozer by using cranial
percussion.

 TB> Since playing Don Q is one of the things I enjoy doing to keep other
 TB> peoples brains flexible I decided to throw my bit of science in the pot
 TB> as well and give you a hand (sort of).

 TB> If you are right there obviously has to be a compensating mechanism,
 TB> I.e. on the surface it seems since the radius is obviously reduced there
 TB> have to be more axle revs for a given distance.

One quibble: a deformed tyre is not a circle, so using the word
"radius" is not correct. I think it's this "radius"
concept that's
given so many people the idea that I'm trying to quash.

 TB> However, the tyre is flattened over a wider area, not just at the point
 TB> of minimum radius.

 TB> For you to be right these extremities of contact with the road have
 TB> to be greater then the original radius, i.e. the tire needs to be
 TB> squared of a bit. That this is the case is easily seen, since it is
 TB> your arguement you can measure and report if the bulge at (two)
 TB> ends with increased radius will indeed compensate for the radius
 TB> reduction in the (one) center.

I did look at that, but I'd need to make a funny jig or two to
measure accurately the distance from the axle to the tyre edge.
This would be especially tricky very close to where the rubber hits
the road, because the bottom arm of the jig would have to be narrow
enough to fit in the gap, but strong enough to do repeatable
measurements accurate to a millimetre or two. Attaching this jig to
the exact centre of the axle would be another problem, perhaps a
small hole would have to be drilled in the hubcap (or bearing
cover, in the case of the van I was using for the test).

 TB> Simply pullling the integral over the linear distance would solve it
 TB> conclusively.

 TB> QED,

 TB> don't thank me:-)

Your father was a hamster, and your mother smelled of elderberries.

Cheers

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