i know this isnt a rally forum, but this seems to be the closest thing. i know rally cars generally run pretty small/narrow tire widths so it can dig into the dirt/gravel. but how small is too small? and how wide is too wide? what is a good compromise? what advantages/disadvantages for running a wider or narrower tire in rally?

 

Well for the U.S. I would say it is whatever size is availbe that fits your car because there arn't many availbe to us.

It's my understanding that in the gravel you wan't a skinny tire to dig in and for snow and ice you want a really skinny tire.

Genreally I think you don't see very wide tires because you need the suspension travel more than you need a wide tire and a wide tire would hit the fender and other things more.

Suspension travel is very important to rally racing.

 

what about a contact patch? im sure just like in road race, or any kind of motorsport, you want the biggest contact patch possible for grip, wouldnt it be the same for rally? but you would have to make a compromise somewhere?

 

kumho makes a rally tire
bottom left of this pic


i think it has a lot to do with tread design so you dont get mud and dirt stuck on the tire often

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by pos_cd5 &raquo;</TD></TR><TR><TD CLASS="quote">what about a contact patch? im sure just like in road race, or any kind of motorsport, you want the biggest contact patch possible for grip, wouldnt it be the same for rally?</TD></TR></TABLE>

The size of the contact patch is determined only by the weight of the car and the amount of pressure in the tires, NOT by the width of the tire. (For example, if all four tires in a 2640-pound Integra Type R are inflated to 33 psi, then the size of the four contact patches will total 80 square inches, regardless of whether they are 175 mm skinnies or 245 mm steamrollers.) However, the width of the tire determines the shape of the contact patch, which is why it is relevant to cornering on racetracks.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ekim952522000 &raquo;</TD></TR><TR><TD CLASS="quote">Well for the U.S. I would say it is whatever size is availbe that fits your car because there arn't many availbe to us.</TD></TR></TABLE>

You got that right.

Gearing is a bigger factor then width as well, especially if you're in a production class and can't put in lower gears.

If you are running 14's you have a choice of 175/65R14 or 185/65R14, although is getting harder to find distributors with the 185 size. 15's you have more a choices of widths and sizes, but again, it can be tough to get something to fit.

What car is this for?

 

this isnt for any car. i dont even rally...haha, i was just curious and wanted to learn something new ...hope you guys dont feel like i wasted your time.