How Common is Poor Tire Bead Seating?

[SubLGT]

In their brochure for an automated tire changer, Hunter Engineering implies that 50% of tire sets have at least one tire with less than optimum tire bead seating, and this can lead to vibration issues. The bead can be sealed against air leakage, but not be completely seated.

http://www.hunter.com/tirechanger/revolution/6724-T.pdf

They write on page 14 of the PDF that the "bead massager" feature on the Revolution Tire Changer can significantly improve 50% of tire sets (defined as one or more tires in the set has a 7lb reduction in road force variation). It does this by having two rollers go around the entire circumference of the bead area.

 

[Tegger]

How common is it? Very.

Poor bead-seating is the bane of tire makers. Poor bead-seating is the #1 cause of tire vibration; it is common among the budget-oriented tire places.

I think Hunter's idea is a really good one, provided the installer used proper tire-lubricant, and laid it on evenly before seating the bead. Those are two things that Hunter still can't control.

 

[The_Jeff]

I wonder what's more likely to seat properly, a bead that pops in at 2 psi with no drama or one that takes unnatural soaking of lube, 50 PSI and hammering. The latter might "bang home" better but the former might flex itself slightly as it continues to inflate.

 

[Tegger]

Originally Posted By: eljefino
unnatural soaking of lube

Please define that phrase.

 

[bigjl]

Only ever seen it after somebody has hit a kerb.

Never had an issue with it on any vehicle i have driven thankfully.

 

[The_Jeff]

Originally Posted By: Tegger
Originally Posted By: eljefino
unnatural soaking of lube

Please define that phrase.


Sloshing around, suspect some is still inside the tire.

 

[SubLGT]

From Hunter engineering:

……………...“Lube is Good!” Proper lubrication on the tire bead AND rim areas including bead seat, hump, balcony, and drop center are vital in achieving proper seating of the tire bead to the wheel assembly. Aggressive acceleration or braking should be avoided for the first 500 miles to prevent tire to wheel slippage……………..

Tire technology is always changing. Today's vehicles require the tire to be designed to tightly adhere to the wheel, preventing slippage between the two components. As a result incorrect tire bead seating procedures are becoming more of an issue in solving vibration complaints. In many cases, a wheel will display high non-uniformity values because of increased tire bead interference, wheel design or improper bead seating procedures. If the tire is re-loosened from the wheel and properly lubricated and remounted, the level of non-uniformity may decrease dramatically. On sensitive vehicles, sometimes there is benefit to slightly over-inflating the tire, deflating the air, and then re-inflating to optimize bead seating………………."

http://www.gsp9700.com/technical/4458T/4458T.htm

 

[CapriRacer]

Originally Posted By: SubLGT
In their brochure for an automated tire changer, Hunter Engineering implies that 50% of tire sets have at least one tire with less than optimum tire bead seating, and this can lead to vibration issues. The bead can be sealed against air leakage, but not be completely seated.

http://www.hunter.com/tirechanger/revolution/6724-T.pdf

They write on page 14 of the PDF that the "bead massager" feature on the Revolution Tire Changer can significantly improve 50% of tire sets (defined as one or more tires in the set has a 7lb reduction in road force variation). It does this by having two rollers go around the entire circumference of the bead area.


I think they are exaggerating the situation.

What normally happens is that the first few miles of vehicle operation flexes the tire enough to get the bead to fully seat. Needless to say, this changes the "roundness" of the tire and wheel assembly. Do some assemblies change significantly? Yes. Whether it is significant in half the cases is debatable.