<VV> Comments On Old Tires

[John Beck]

Drag racers call this "tire shake".  A top fuel driver I once worked
with described it as like having your helmet clamped in a paint shaker. 
Looks cool in slow motion but I don't think I'd like to drive through
it.  --J.B.

Smitty Smith wrote:
> 
> One thing I remember that may have a major impact on old rubber failing is a thing called a "standing wave".  At some speed and increasing with speed, the tire smacks the pavement and rebounds.  At the same time the part of the tire that was carrying the weight snaps back round (so to speak) and even goes beyond round.  The two together create a bulge in the tread right behind the contact patch.  This bulge of course snaps back in and over travels again.  This action continues for maybe up to 8 inches behind the contact patch.  When you see it in photographs it looks like a flag waving in the wind.