View Full Version : Tire Balancing


Racer X-8
08-12-2003, 10:12 PM
A friend at work informed me that my tires were installed wrong, and because of that, I had a whole lot of counterweights added to my rims to account for it.

He said that, on the sidewalls of the tires, the red dots on the right and the blue dots on the left should be oriented opposite the valve stems.

I think he said that the dots mark the heavy point of the tire. To minimize required counterweights, the heavy side of the tire should be opposite the valve stem because the valve stem creates the heavy side of the wheel. So, the two heavy sides should be opposite each other to minimize the out-of-balance condition that is then corrected by adding counterweights. Any unneccessary counterweights make the whole assembly heavier, more polar moment of inertia to have to spin, reducing power output efficiency a little.

My red/blue dots are oriented at the valve stems & my counterweights look to be a lot, like about 4" in length.

I wonder if the pressure sensors have anything to do with this?

highspeed8
08-12-2003, 10:58 PM
My tire's colored dots are at valve stems, and LOTS of counter weights, about 15 each wheel...

eccles
08-13-2003, 12:37 AM
Originally posted by Racer X-8
A friend at work informed me that my tires were installed wrong, and because of that, I had a whole lot of counterweights added to my rims to account for it.

He said that, on the sidewalls of the tires, the red dots on the right and the blue dots on the left should be oriented opposite the valve stems.Your friend is blowing smoke. This page (http://www.trucktires.com/library/publications/periodicals/RealAnswers/97V1Issue2/Doctor.htm), this page (http://www.nsxprime.com/FAQ/TireWheel/Balancing.htm) and this page (http://www.us.metzelermoto.com/product_info/glossario/safety.html) all concur that the red (or yellow, if present) dots should be aligned with the valve stem (unless the wheel is specifically marked to indicate the heavy point of the rim).

On most modern alloy wheels, the imbalance of the bare wheel is pretty negligible, but the extra weight of the TPMS sensors on the RX-8 wheels means that the valve stem is always going to be the heaviest point of the wheel. The reason we have so many weights opposite the valve is to offset the extra weight of the sensor.

If the red dot wasn't aligned with the stem, then the tire's inherent imbalance (however small) would be working against getting the whole assembly in balance, and we'd need even more weights.

Racer X-8
08-13-2003, 01:17 AM
Right you are! Good info. Looks like I have a tire mounting course to give my buddy tomorrow (today! I better go to bed!!!:eek: )

Thanks!!!