i****x
发帖数: 17565 | 1 因为大马力车需要更大的接地面积提供更好的抓地力，而轮胎接地区域大致是个椭圆形
。大轮胎直径可以增加这个椭圆形的长，而宽轮胎可以增加它的款。为了操控中性舒适
，接地区域的长宽比应该有个最佳比例（不一定是正圆最好）。所以高性能车要增加接
地面积，必须长宽成比例增加，也就是直径更大轮胎更宽。
至于同样轮胎直径下为什么高性能车轮毂更大，常见的有三个理由。第一是容下更大刹
车。第二是增加操控sharpness，因为转向时轮胎会被抓地力挫歪，轮胎壁越窄这个形
变就越小，同时轮胎内部本身容积减小，等效于增大了轮胎的弹力系数让它变得更硬。
第三是有说法讲轮毂越大轮子总质量越轻，因为轮毂中间的绝大多数空间都没有质量。
我记得是在gt5的官方手册里看到的。 |
s*****8
发帖数: 606 | 2 Theoretically, thinner & wider tires should have same amount of the contact
patch comparing with skinny & thicker tires. The difference are, wider tire
will have more lateral force and thicker tire will have more vertical force.
That’s one of the reason drag race use thicker tires.
I used to ask the difference between using 17 inch vs 18 inch in the racing
forum, most people cannot tell the difference unless cheaper tires in 17’s
and more options in 18’s. There must be a difference, but I have no clue~ .
Most mid size track/race cars will use 18” rim or 17” but rarely 19” or
20”, it must means something beyond the cost. I think the big rims in super
sports car are more for looking. |
x*b
发帖数: 5723 | 3 那为什么GT3这类车还要用20的？貌似Porsche说991 GT3的20寸轮毂比997的19寸轮毂还
轻，而且together with the new tires will provide better performance。
contact
tire
force.
racing
s
.
super
【在 s*****8 的大作中提到】
: Theoretically, thinner & wider tires should have same amount of the contact
: patch comparing with skinny & thicker tires. The difference are, wider tire
: will have more lateral force and thicker tire will have more vertical force.
: That’s one of the reason drag race use thicker tires.
: I used to ask the difference between using 17 inch vs 18 inch in the racing
: forum, most people cannot tell the difference unless cheaper tires in 17’s
: and more options in 18’s. There must be a difference, but I have no clue~ .
: Most mid size track/race cars will use 18” rim or 17” but rarely 19” or
: 20”, it must means something beyond the cost. I think the big rims in super
: sports car are more for looking.
|
d******e
发帖数: 7844 | 4 赛车只有18是因为，已经足够装下顶级的刹车了。
再大只会增加不必要的重量。
contact
tire
force.
racing
s
.
super
【在 s*****8 的大作中提到】
: Theoretically, thinner & wider tires should have same amount of the contact
: patch comparing with skinny & thicker tires. The difference are, wider tire
: will have more lateral force and thicker tire will have more vertical force.
: That’s one of the reason drag race use thicker tires.
: I used to ask the difference between using 17 inch vs 18 inch in the racing
: forum, most people cannot tell the difference unless cheaper tires in 17’s
: and more options in 18’s. There must be a difference, but I have no clue~ .
: Most mid size track/race cars will use 18” rim or 17” but rarely 19” or
: 20”, it must means something beyond the cost. I think the big rims in super
: sports car are more for looking.
|
d******e
发帖数: 7844 | 5 991 GT3毕竟是road car，20寸还是为了抓眼球。
真跑杯赛的991 GT3 Cup轮子就是19的。
【在 x*b 的大作中提到】
: 那为什么GT3这类车还要用20的？貌似Porsche说991 GT3的20寸轮毂比997的19寸轮毂还
: 轻，而且together with the new tires will provide better performance。
:
: contact
: tire
: force.
: racing
: s
: .
: super
|
i****x
发帖数: 17565 | 6 “wider tire will have more lateral force and thicker tire will have more
vertical force.”
这就是我说的接地形状的问题。宽胎接地形状是肥的，大胎接地形状是瘦的。
“I think the big rims in super sports car are more for looking.” most true
contact
tire
force.
racing
s
.
super
【在 s*****8 的大作中提到】
: Theoretically, thinner & wider tires should have same amount of the contact
: patch comparing with skinny & thicker tires. The difference are, wider tire
: will have more lateral force and thicker tire will have more vertical force.
: That’s one of the reason drag race use thicker tires.
: I used to ask the difference between using 17 inch vs 18 inch in the racing
: forum, most people cannot tell the difference unless cheaper tires in 17’s
: and more options in 18’s. There must be a difference, but I have no clue~ .
: Most mid size track/race cars will use 18” rim or 17” but rarely 19” or
: 20”, it must means something beyond the cost. I think the big rims in super
: sports car are more for looking.
|
q**j
发帖数: 10612 | 7 我觉得你提出的三点都不是必须的。第一，装刹车一定大小就行了，比如前面说的19就
够了。第二个可以多打气。第三个可以用轻量的材料一定程度弥补。
我觉的一个重要原因是轮子大了，相当于杠杆作用的力矩大了，所以不容易被轴转动。
【在 i****x 的大作中提到】
: 因为大马力车需要更大的接地面积提供更好的抓地力，而轮胎接地区域大致是个椭圆形
: 。大轮胎直径可以增加这个椭圆形的长，而宽轮胎可以增加它的款。为了操控中性舒适
: ，接地区域的长宽比应该有个最佳比例（不一定是正圆最好）。所以高性能车要增加接
: 地面积，必须长宽成比例增加，也就是直径更大轮胎更宽。
: 至于同样轮胎直径下为什么高性能车轮毂更大，常见的有三个理由。第一是容下更大刹
: 车。第二是增加操控sharpness，因为转向时轮胎会被抓地力挫歪，轮胎壁越窄这个形
: 变就越小，同时轮胎内部本身容积减小，等效于增大了轮胎的弹力系数让它变得更硬。
: 第三是有说法讲轮毂越大轮子总质量越轻，因为轮毂中间的绝大多数空间都没有质量。
: 我记得是在gt5的官方手册里看到的。
|
h****y
发帖数: 9234 | 8 多打气接地面积就小了.抓地力会减的..
【在 q**j 的大作中提到】
: 我觉得你提出的三点都不是必须的。第一，装刹车一定大小就行了，比如前面说的19就
: 够了。第二个可以多打气。第三个可以用轻量的材料一定程度弥补。
: 我觉的一个重要原因是轮子大了，相当于杠杆作用的力矩大了，所以不容易被轴转动。
|
i****x
发帖数: 17565 | 9 二说反了。三轻量材料谁都能用，最后还是大轮胎更轻。三点当然都不是必须的，只是
设计选择而已。
★ 发自iPhone App: ChineseWeb 8.2.2
【在 q**j 的大作中提到】
: 我觉得你提出的三点都不是必须的。第一，装刹车一定大小就行了，比如前面说的19就
: 够了。第二个可以多打气。第三个可以用轻量的材料一定程度弥补。
: 我觉的一个重要原因是轮子大了，相当于杠杆作用的力矩大了，所以不容易被轴转动。
|
y******e
发帖数: 1194 | 10 胎壁高的轮胎在高速转动的时候整个轮胎会变窄，抓地力下降，所以性能车会选择大轮
毂，变相的把胎壁变矮。 |
s*****8
发帖数: 606 | 11 今天刚好看到书上说'why wider tires are better'（对于侧向力=过弯来说wider好）
抄一段原话，不是debate，仅供参考。 有点离题了，只是想分享下，希望op不介意
for the same vertical load and internal pressure, a tire with a wider tread
has a shorter, wider contact patch than a narrower tie. the area of both
contact patches is the same if the internal pressure and load are the same.
in the section on lateral tread deformation we showed that deformation
builds up along the length of the contact patch until the restoring force of
the tread and carcass exceeds tread grip and sliding begins.
a shorter contact patch at the same slip angle begins to slip at roughly the
same distance from the leading edge as with a longer contact patch. but the
shorter contact patch has more of its length stuck to the road than the
longer, narrower contact patch;and therefore a larger portion of its overall
area is gripping. a larger portion of contact patch area gripping means
more total grip. so for the same load and same slip angle, a wider contact
patch generates more grip than a narrow contact patch. |
c***x
发帖数: 628 | 12 胎壁高其实抓地力才强，纯粹为抓地力的话胎壁越高越好。你去看看专门直线竞速的车
就知道了。
【在 y******e 的大作中提到】
: 胎壁高的轮胎在高速转动的时候整个轮胎会变窄，抓地力下降，所以性能车会选择大轮
: 毂，变相的把胎壁变矮。
|
i****x
发帖数: 17565 | 13 没错，这正是我的point，轮胎大小和宽窄决定了接地面的形状胖瘦，而那个形状决定
了车的handling特性。
tread
.
of
the
the
【在 s*****8 的大作中提到】
: 今天刚好看到书上说'why wider tires are better'（对于侧向力=过弯来说wider好）
: 抄一段原话，不是debate，仅供参考。 有点离题了，只是想分享下，希望op不介意
: for the same vertical load and internal pressure, a tire with a wider tread
: has a shorter, wider contact patch than a narrower tie. the area of both
: contact patches is the same if the internal pressure and load are the same.
: in the section on lateral tread deformation we showed that deformation
: builds up along the length of the contact patch until the restoring force of
: the tread and carcass exceeds tread grip and sliding begins.
: a shorter contact patch at the same slip angle begins to slip at roughly the
: same distance from the leading edge as with a longer contact patch. but the
|
s*****8
发帖数: 606 | 14 https://www.youtube.com/watch?v=o6Glkf4jwkM
看到这个视频，7:18秒开始性能测试18“，19”轮子，不过18“的用225/245胎，19”
的用245/275的胎，在侧向力上是不等的，不晓得为什么这么选。 |
