Comments by "Mikko Rantalainen" (@MikkoRantalainen) on "The Surprising Science Behind Tread Patterns" video.

If I remember correctly, rubber also has shear strength which means that for a given sideways force there's optimal weight per cm² where the rubber can handle the sideways load without tearing. Cases where using wider tires improves performance are usually the cases where the surface of narrower tire is sheared away due exceeding structural integrity of the rubber.
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@PhaunDubstep Weight on tire is not constant. When you take a sharp corner with a car the outside tires handle way more weight hand the inside tires. If the car is decelerated or accelerated at the same time (common in racing) there will be weight difference between front and rear, too. Then there're dynamic forces, too. When the weight distribution between the forces transferred via springs, suspension dampers and anti-rollbars all have some force transfer delays which separate the weight of the vehicle from the weight applied on tires for short periods of time. For optimal performance you would want enough weight to press the thread compound into the surface roughness but small enough weight to not exceed the shear strength. And keeping the weight on that (often pretty narrow) range is very hard with the dynamic weight distribution going all around during racing. Good computer simulations such as BeamNG, iRacing and rFactor all consider these dynamic forces and I think all of those also include tire deformation, too.
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@jonathangaray7794 In my experience "wheel" in context of cars can mean just the rim, the combination of tire + rim or the steering wheel. You just have to guess from the context which interpretation should be used for each content.
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@Michael Peck Are you sure about that? I would expect car to be both suspended from the top of the tire and supported from the bottom, too. The exact ratio changes according to air pressure and rotational speed of the tire. For example, see how top fuel dragster tires deform during the acceleration.
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@Michael Peck I agree that the wheel is partially suspended from the top of the wheel. However, imagine following though experiement: take a normal car tire with a rim. Cut the top half of the tire totally away. Does the rim drop down to ground? Absolutely not, the tire has mechanical structure, too. Is the suspension power reduced? Absolutely yes. Of course, the tire design makes a huge difference on the mechanical structure. WRC rally cars use tires with so strong sidewalls that they can keep driving even with deflated tires. In tat case, the traction is heavily reduced but not zero.
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@Michael Peck Umm... what? If you cut the tire half (removing everything above the axle) the air pressure difference between the "inside" of the wheel and above the wheel is literally zero (or technically about 1 Pa if you measure about 30 cm above the cut because that's the pressure difference in atmosphere per height). I agree that different tires have very different sidewall strength. If you include bicycle tires, the lightweight tires are really really thin and flexible.
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