Radial tires static camber.

[Shashi]

After much hunting, I still have a hard time figuring why radial tires need around -3deg of camber(a generalization) while bias ply tires require a lower negative value?

Also, I noticed the wordings usually used with cambers associated with radial tires. It goes that radials are more tolerant of negative camber than bias ply tires. I think this has got to do more with the way the cyclic stresses are distributed in the carcass and the sidewalls, which radials are better at than the bias ply. Could you guys please help me understand this better?

Another thing that I was considering was the fact that the contact patch area of a radial remains constant with a varying lateral load. So it wouldn't matter whether the tire has -3 or -1.5 deg static camber. But is there any advantage of having a higher negative static camber for radials?

[ben]

Radial tyres generally speaking have softer upper sidewalls than crossplies this means that the carcass will deflect laterally by a greater amount in a corner.

Adding negative camber ensures that once this deflection takes place you have a decent contact patch shape in the corner.

There are lots of complicated explantions to do with camber thrust, but that is fundamentally the reason.

Ben

[BillCobb]

Radial tires in General (also Goodyears, Michelins, Avon, Hoosier, Kumho, etc. have lower camber stiffness under the same conditions (load, pressure, rim dimensions, etc) but the main benefit to your query is shorter relaxation distance.

[Zac]

Bill is always good for a tire joke.

Oddly enough, they finally finished tearing down the old General Tire Tech Center this week.

[BillCobb]

Relax, They are pretty good when I get in the groove. They should start another tread dealing with just tyre jokes. Maybe I should stem the ride right now before I get belted. My biased reply still stands. Same for other alignments (toed you so...).

[Zac]

too far