Steer tire on drives?

I'll try again. if you put a sting around each and marked the length the shorter tire would have a shorter string. Right? If you laid both strings side by side that is how far each tire would go in a single revolution. Right? The problem. they both have to go the same distance when they are bolted together. Which means one has to be slid a little. How much? The difference is the same as the difference in the two strings. Which tire gets slid? The one that has the least traction which is the one that carries the least weight. And that would be the the shorter of the two.

 

I'm pretty sure I get what is being said.
(1)Revolutions are the same as they are bolted together we agree.
(2)The road distance they travel is equal we agree.
(3)The larger tire has a greater circumference so it covers more road distance each time it does a revolution than a smaller tire in theory.
(4) Because the two tyres are bolted together they are forced to operate at the same RPM and because the larger covers a greater distance in the same number of revolutions the smaller is dragged a bit to make up the extra distance.

There is just a major flaw in that theory.
If a tire was 6 inches smaller it would not touch the ground so it would not wear.
The only time on a flat road that the smaller tire would come into contact with the road is when the larger tire was deformed to a point where the measurement from the centre of the axle to the road was at least as small as that of the smaller tyre.
On steel wheels (Inflexible) this won't happen and the smaller will just clear the road.
On pneumatic rubber tires there is deflection so that the radius from the center of the axle to the road is the same for the larger and smaller so at that point (Point of contact) they are moving at the same linear speed so the one is not being dragged.
There obviously is a reason but it's not this as far as I can see.

 

Federal law states " recaps are legal for use on the steers, regrooved are illegal"

 

I got that from a reputable source...I believe it was straight from an instructional video on either Michelin or Goodyear's own commercial tire website.

 

I used to think that the larger/newer one would wear faster, because as you pointed out, it is deformed more. Regardless, they won't wear at the same rate if there is a size difference.

 

When I drove for Marten, we all carried a spare steer tire. That way any tire shop could mount it on any rim for any of the 18 tires. Then next time we went to a company terminal they would put the correct tire on.

 

Sounds like a job for Mythbusters

 

to late for that to happen

 

Improperly matched duals are subject to rapid tread wear because the larger tire carries more load and will wear fast and unevenly. Although the mismatched duals have different diameters, they must rotate at the same speed. The smaller tire then also wears unevenly because it is forced to scuff over the road. The overall result is abnormal and unequal tread wear for both tires.

This info taken from here.... http://www.retread.org/#!buses-and-retreaded-tires/ct47

 

There's a lot involved here, circumference, tread depth, air pressure, rubber compound, load range, etc., to predict which one will wear first. Adjusting the air pressure to balance weight will lead to the tire with less air (obviously the taller tire) to get hotter. It would be a fine art to master!

I think open lug drives on OTR rigs is mostly a carry-over from car ownership. An old truckers belief like tranny oil in the fuel filter and oil additives. I get on plenty of jobsites with my steer axle tread on the drives and have no trouble.

Listening to those open lug tires sing and whine whizzing past while you're sleeping in the pickle park ain't all that either. Closed shoulder tires are nice and quiet.