Oh God, not more of this nonsense from john1701a again. Well, never let it be said that being completely uninformed ever kept you from posting a response.john1701a said:
Yes, and those bikes are all about acceleration, not cornering.priusenvy said:Ever seen the rear tire on a high performance motorcycle? They're wider than the Prius tires. Do I need to go on?
You have it correct. The shape is longest in the direction it needs to RESIST force better. Long and narrow is good because it provides more SIDEWAYS resistance. Wide and short is better for acceleration because it provides more WIDTH of space to generate that force.priusenvy said:The tire contact patch on a wider tire (all other relevant variables held constant such as tire pressure and diameter) will be wider and shorter compared to a narrower tire. With a wider contact patch, the pressure will be more consistant across the face of the contact patch compared to a narrower, longer contact patch when cornering. This is why the wider tire can generate higher cornering forces at lower slip angles. Grossly simplified, a contact patch whose shape is longest in the direction it needs to resist force is better. Long and narrow is generally better for generating longitudinal acceleration (acceleration and braking), and short and wide is generally better for generating lateral acceleration.
Hardly. If that were the case, they would have square shoulders. Ever seen a MotoGP race from the viewpoint of a bike-mounted camera?ehurtley said:Yes, and those bikes are all about acceleration, not cornering.
You've got it backwards. Period. You know about as much about friction and tire dynamics as you do about the source of the technology in the Ford Escape's powertrain (you were proven completely wrong there too).You have it correct. The shape is longest in the direction it needs to RESIST force better. Long and narrow is good because it provides more SIDEWAYS resistance. Wide and short is better for acceleration because it provides more WIDTH of space to generate that force.
Wrong analogy - which is why it leads you to the wrong conclusion. Ice skates carve into the ice with their edge, it's not even an application of friction. Try your experiement with a rectangular brick.Example: Try pushing a snow shovel along concrete. Push it the 'normal' way, with the blade scraping along the wide direction in front of you. More resistance. More force needed. Now try pushing it side-to-side so it's narrow end is what is scraping. | -> vs. - -> It slides more easily. That's because even though the same surface area is sliding along the ground, you're making it slide differently. Now try 'turning' the shovel each way while sliding. The wide direction forward turns poorly, and tends to slip and slide as it does so. The narrow direction forward turns easily. (Like an ice skate, turning without slipping sideways.) A wide tire is like the shovel scraping the way it's meant to be used. Wide area providing lots of friction. A narrow tire is like the narrow end first. Turns on a dime, like an ice skate.
Again, that's completely backwards.Conclusion: A wide tire is good for acceleration and braking, a narrow tire is good for cornering. Please note that this only counts for 'all other things equal' tires.
That pretty much tells me and others everything I need to know about the technical content of anything you might post in the future, and your analytical abilities.P.S. Please don't resort to personal attacks. It makes you look childish. I'm sorry, but John is one of the most informed posters on here.
Whoop de doo. I did get my engineering degree, and it's from a school that would take about two minutes to reject your application.P.P.S. I studied aerospace engineering in college, and know all about force and friction. (Didn't get my degree, got sidetracked; completed 3+ years, though.)
priusenvy said:Oh God, not more of this nonsense from john1701a again. Well, never let it be said that being completely uninformed ever kept you from posting a response.
Cars and bicycles are designed around completely different design parameters. Bicycles have maybe 1/3hp tops and a power to weight ratio at least twenty times less than that of a car. Cars don't lean into turns. Ultra light weight and ultra low rolling resistance aren't an issue in a car because a human being isn't providing the motive force. Car tire pressures are not 100+ psi. Ever seen the rear tire on a high performance motorcycle? They're wider than the Prius tires. Do I need to go on?