Tire clearance
Thread Starter
Le Mans Master
Joined: Aug 2005
Posts: 5,130
Likes: 3
From: Winter Park FL
Tire clearance
I know theres a quite a few guys with 19" rims up front. Is anybody having any issues with rubbing the inner front wheelwell on a 255/35/19? I never heard of anybody having any problems with this size tire. In fact, that tire size is recomended by the vendor that sells these wheels but I get a rubbing when I make a sharp turn. If I turn the wheel sharp to the right the outer lip of the left tire will rub the front of the wheelwell I believe. Can this be fixed with a smaller tire?
Melting Slicks
Joined: Nov 2003
Posts: 2,887
Likes: 2
From: Macomb MI
St. Jude Contributor
Dam! 19s in the front, kind of a tall rim isn't it.
I'm about to install a set of 18x9.5 in front with 275/40/18 Nitto and 305/35/19 in the rear on a 19x11 rim, I hope I don't have the same issue.
I'm about to install a set of 18x9.5 in front with 275/40/18 Nitto and 305/35/19 in the rear on a 19x11 rim, I hope I don't have the same issue.
Thread Starter
Le Mans Master
Joined: Aug 2005
Posts: 5,130
Likes: 3
From: Winter Park FL
Maybe it is a wheel offset problem
Safety Car
Joined: Feb 2001
Posts: 3,725
Likes: 53
From: Warrington Pa.
I'm running 265/35/18 in front with no problem at all, and 305/30/19 in the rear. The overall roll out is the same as a stock Z06. No traction control or ABS codes and no rubbing. I'm running the proper offset for a C5. Here's the proper offset you need..56mm in front, and 63mm in back
Le Mans Master
Joined: Sep 2000
Posts: 6,101
Likes: 44
From: ABQ NM
Cruise-In II Veteran
I'm running 265/35/18 in front with no problem at all, and 305/30/19 in the rear. The overall roll out is the same as a stock Z06. No traction control or ABS codes and no rubbing. I'm running the proper offset for a C5. Here's the proper offset you need..56mm in front, and 63mm in back
Le Mans Master
Joined: Sep 2000
Posts: 6,101
Likes: 44
From: ABQ NM
Cruise-In II Veteran
A 40 profile strikes me as too tall; me thinks a 35 profile would be better.
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Safety Car
Joined: Feb 2001
Posts: 3,725
Likes: 53
From: Warrington Pa.
The offset of a vehicle's wheel is the distance between the centerline of the wheel and the plane of the hub-mounting surface of the wheel. It can thus be either positive or negative, and is typically measured in millimeters. Offset has a significant effect on many elements of a vehicle's suspension, including suspension geometry, clearance between the tire and suspension elements, the scrub radius of the steering system, and visually, the width of the wheel faces relative to the car's bodywork.
Zero Offset - The plane of the hub mounting surface is even with the centerline of the wheel.
Positive Offset - The plane of the hub mounting surface is shifted from the centerline toward the front or outside of the wheel. Positive offset wheels are generally found on front wheel drive cars and newer rear drive cars.
Negative Offset - The plane of the hub mounting surface is toward the back or brake side of the wheel's centerline.
"Deep dish" wheels typically have negative offset or a very low positive offset.
To maintain handling characteristics and avoid undue loads on bushings and ball joints, the car manufacturer's original offset should be maintained when choosing new wheels unless there are overriding clearance issues.
Wheels are usually stamped with their offset using the German prefix "ET", meaning "Einpresstiefe" or, literally, "insertion depth". An example would be "ET45" for a 45mm offset.
Calculating the offset of a wheel is a fairly easy mathematical equation. First, measure the overall width of the wheel (remember, just because a wheel is 18x7.5, does not mean that the OVERALL width is 7.5”. It means that the measurement between the outboard flange and the inboard flange is 7.5”). Next, divide that width of the wheel by two; this will give you the centerline of the wheel.
Overall width/2 = Centerline
After determining the centerline, measure from the hub-mounting surface of the hub to the edge of the inboard flange (if the wheel were laying flat on the ground – face up – your measurement would be from the ground to the hub-mounting surface). This is your back spacing.
Back Spacing - Centerline = Offset in Inches
Inches x 25.4 = Offset in mm
Last edited by Bill Vett; Apr 6, 2008 at 02:41 AM.
