Learn Me: Wider tires = more Grip? = Faster cornering?

Kenny_McCormic wrote: In reply to blueafro: See my example above, the tires are sticky, like tape, more area=more adhesion. If you listen closely to a high power car you can actually hear the tearing noise the tires make when the car makes a pass once it gets a few hundred feet away and the exhaust isn't as loud.

Except for given pressure, they'll have the same size contact patch regardless of shape. I can understand why the shape of the contact patch allows higher slip angles in cornering, but how does it help in a straight line?

Maybe I'm just thick, but I remain puzzled. :)

In reply to blueafro:

Your assumption is true only as long as you are talking about an item with a lot of elasticity and little restraint in its shape; like pressing down on a balloon. In that case you are correct, contact patch will only be weight and pressure dependent.

However, a tire is restrained in its shape; that is to say that it can only deform a little bit until the rim and cords in the tire itself force it to stay in a shape similar to its non weight bearing shape. As it gets more weight on it or less pressure, the contact patch will get larger to a certain extent, but at some point the rim will pull up on the tire, forcing it away from the ground.

This is especially true as the tire gets more low-profile, it is constrained front to back by its lack of elasticity overall. So we go wider to increase contact patch.

Hope that helps? J

In reply to Warren v:

Wrong. Get yourself a collection of Miata donut spares. Now find a local empty parking lot. Have fun.

Yeah, but the fun doesn't last for long with those.

We're stashing them at the shop for the next slow Exocet we build. XP-3 is too dangerous on anything less than r-comps.

In reply to Jcamper:

Thanks. That's getting me there. I'll need to do some more reading before I can call it intuitive, but this helps. I'd not previously considered how the nature of the contact patch would differ in the two axes, i.e., to the sides where there is a sidewall vs. towards the front and back where the tire curves away from the road.

Tire theory gets less intuitive the further you go down the rabbit hole. It's just as tricky as aerodynamics. You can make general inferences, but you have to make a ton of assumptions to do so.

And once you think you understand it you switch to bias-play racing tires and have to start over again...