Center Rib Chamfer on Autocross BFGs

[BlueHPP]

I am running my 2020 HPP Ecoboost in D street. I have a tire question, running the 275/35/19 BFGs on the 9.5 inch rims. I have 65 runs, 35 on asphalt and 30 on grippy WWII airfield concrete, in that order. I am seeing the center rib chamfer and ask is this the result of high/low tire pressure or just tire geometry. The drop is about 1.5 32nds of an inch. Overall tire ware is good considering the weight of the car and 65 runs. I have been rotating the tires from front to back and have mostly even wear. This is really only a problem when I have to flip the tires and the tire shop gets concerned about the wear down to 2/32 and then will not flip them, even when there is plenty of tread both sides of the center rib. Tire pressures are 32-33/31 front/rear and tire temperatures (F) taken on asphalt are even across the rear and hot on the outside edges in front. I have -1.6 camber front and -1.4 rear. Going to adjust the rear to -1.5.
Any experienced opinions?

	Outside L	center	Inside		inside	center	Outside Right
Front	133​	131​	130​		143​	142​	151​	33​
Rear	131​	135​	136​		141​	141​	141​	31​

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[Dana Pants]

Chamfer is normal. Being rejected by tire shops is normal. My advice is to flip before you reach the wear bars or figure out how to mount tires yourself. Machines pay for themselves if you keep autocrossing.

 

[kz]

This is absolutely normal. Not enough front camber but even with -2.x which is max you can being street legal, you'd see same thing. Find a different place to mount the tires.

 

[Brian@BMVK]

2x to what the guys above said.

Also you'll thank yourself by using the available limits of street class camber allowances via slotting the strut mounting hole to get around -2.0. Better grip and better wear.

 

[strengthrehab]

I get the same thing...same tire with -3.0 camber.

 

[BlueHPP]

Thanks guys for the input. Reinforced what I was thinking.

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